Μεταβολές στη δομή και τη λειτουργία του εγκεφάλου εφήβων και νεαρών ενηλίκων με ψυχογενή ανορεξία, όπως αυτές αναδεικνύονται απεικονιστικά: συστηματική ανασκόπηση Η αναστρεψιμότητα των μεταβολών μετά τη θεραπεία: συστηματική ανασκόπηση

Η νευρική ανορεξία αναγνωρίζεται ως ψυχιατρική νόσος με σημαντική νοσηρότητα που επιφέρει μεταβολές σε σώμα και εγκέφαλο νεαρών ασθενών. Ωστόσο, οι μεταβολές στον εγκέφαλο των ασθενών παραμένουν αβέβαιες. Αυτή η συστηματική ανασκόπηση αποσκοπεί στο να διαπιστώσει πώς η θεραπεία και η ανάκτηση βάρους επιδρά στις εγκεφαλικές δομές ατόμων με νευρική ανορεξία. Διεξήχθη στις βάσεις δεδομένων PubMed, ScienceDirect και Cochrane από την έναρξη τους έως τον Ιανουάριο του 2020. Συμπεριελήφθησαν προοπτικές μελέτες που εξετάζουν νευροαπεικονιστικες μεταβολές σε εφήβους και νεαρούς ενήλικες έως 24 ετών με νευρική ανορεξία πριν και μετά την αύξηση ή την αποκατάσταση του σωματικού βάρους. Ο έλεγχος, η εξαγωγή δεδομένων και η μεθοδολογική αξιολόγηση της ποιότητας πραγματοποιήθηκαν από τουλάχιστον 2 ερευνητές ανεξάρτητα, ακολουθώντας τις οδηγίες PRISMA. Συμπεριλήφθηκαν δώδεκα μελέτες σε δεκατρία άρθρα (238 ασθενείς). Από τις μελέτες με MRI αναδεικνύεται η αναστρεψιμότητα των μετρήσεων επιφανειών και όγκων δομών του εγκεφάλου σύντομα μετά τη θεραπεία, αν και ελλείμματα όγκου της φαιάς ουσίας εξακολουθούν να υφίστανται και μετά την ανάκτηση βάρους, γεγονός που υποδηλώνει την ύπαρξη ενός μη αναστρέψιμου στοιχείου. Οι μελέτες που χρησιμοποίησαν DTI δείχνουν ότι η αναδόμηση συμβαίνει και σε επίπεδο οργάνωσης νευρικών ινών. Το κύριο εύρημα των ερευνών SPECT είναι η αύξηση στην περιφερειακή ροή του εγκεφαλικού αίματος (rCBF) σε ορισμένες περιοχές του εγκεφάλου μετά τη θεραπεία. Συμπερασματικά η θεραπεία της νευρικής ανορεξίας, αποκαθιστά τις περισσότερες εγκεφαλικές αλλοιώσεις, αν και δεν μπορούν να εξαχθούν οριστικά συμπεράσματα λόγω λίγων δεδομένων. Η κατανόηση των μηχανισμών στις οποίες βασίζονται αυτά τα ευρήματα μπορεί να παρέχει σημαντικές προληπτικές δυνατότητες.Importance Anorexia nervosa is recognized as an important cause of morbidity a psychiatric disease with a severe impact on the body and brain of young patients. However, changes in patients' brains remain uncertain.  Objective To evaluate how treatment and weight recovery affect the brain structures of young patients with anorexia nervosa. Data Sources PubMed, ScienceDirect, and Cochrane from database inception to January 2020. Study Selection Prospective studies examining the neuroimaging changes in adolescents and young adults up to 24 years of age with anorexia nervosa before and after weight gain or weight normalisation.  Data Extraction and Synthesis Screening, data extraction, and methodological quality assessment were performed by at least 2 researchers independently, following the PRISMA guidelines. Main Outcomes  Most findings appear to quickly reverse after weight gain.  Results Twelve studies published in thirteen articles (238 participants with anorexia nervosa) were included. MRI studies indicate reversibility of volumetric lesions soon after treatment, although gray matter volume deficits persist after weight gain, suggesting the existence of an irreversible element. Studies using DTI show that remodeling also occurs at the level of nerve fiber organization. The main finding of SPECT studies is the increase in regional cerebral blood flow (rCBF) in certain areas of the brain after treatment.   Conclusions and Relevance Treatment of anorexia nervosa, restores most of the patient's brain lesions, although definite conclusions could not be drawn due to scarce data from longitudinal studies. Understanding the mechanisms underlying these findings could have important preventive potential.

Διερεύνηση Απόψεων και Στάσεων Εκπαιδευτικών για τα Ατυχήματα σε Σχολεία Πρωτοβάθμιας Εκπαίδευσης

Εισαγωγή: Τα σχολικά ατυχήματα στη χώρα μας συγκροτούν ένα καίριο δημόσιο πρόβλημα υγείας. Συνήθως οι τραυματισμοί που καταγράφονται στο σχολείο, συμβαίνουν κατά τη διάρκεια των διαλειμμάτων και κατά τη διάρκεια της γυμναστικής. Η φυσική δραστηριότητα των παιδιών είναι ο πιο σημαντικός παράγοντας που συμβάλλει στον υψηλό κίνδυνο τραυματισμού. Σκοπός: Σκοπός της παρούσας μελέτης είναι να διερευνήσει τις απόψεις και στάσεις εκπαιδευτικών για τα ατυχήματα σε σχολεία πρωτοβάθμιας εκπαίδευσης. Δείγμα - Μεθοδολογία: Τα δεδομένα της έρευνας συνελέγησαν από 155 εκπαιδευτικούς κατά το Μάρτιο 2019, χρησιμοποιώντας ως εργαλείο συλλογής ένα ανώνυμο ποσοτικό ερωτηματολόγιο. Αποτελέσματα: Το δείγμα αποτέλεσαν συνολικά 155 εκπαιδευτικοί, 120 γυναίκες (77,4%) και 35 άνδρες (22,6%) με μέση ηλικία 40,9 έτη. Τα ευρήματα της μελέτης έδειξαν ότι κυρίως τα ατυχήματα συμβαίνουν στον προαύλιο χώρο του σχολείου, στους διαδρόμους του κτιρίου και εντός των αιθουσών διδασκαλίας. Τα ατυχήματα που λαμβάνουν χώρα είναι συγκρούσεις μεταξύ των παιδιών, πτώσεις, άσκηση επιθετικότητας, αιμορραγίες, και κακώσεις. Οι εκπαιδευτικοί, δεν έχουν την κατάλληλη νομική κάλυψη – κατοχύρωση από τους θεσμικούς φορείς ώστε να αντιμετωπίσουν κάποιο σχολικό ατύχημα. Αναφορικά με το είδος των ατυχημάτων συνήθως το 16,6% είναι συγκρούσεις, το 14,2% αιμορραγίες/ρινορραγίες, το 12,2%πτώσεις από ολισθηρό δάπεδο και το 5,7% κακώσεις. Γενικά αντιμετωπίζονται με πρώτες βοήθειες εντός του σχολικού περιβάλλοντος 39,3% και κατά το 38% των περιπτώσεων καλούνται οι γονείς να παραλάβουν τον μαθητή. Υπάρχουν όμως και σοβαρότερα ατυχήματα όπως οι πτώσεις και οι κακώσεις που χρήζουν ανάγκη για μεταφορά του μαθητή σε νοσοκομείο/κέντρο υγείας ή κλήση του ΕΚΑΒ. Τέλος, σημαντικό εύρημα αποτελεί ότι οι εκπαιδευτικοί θεωρούν ότι τα προγράμματα αγωγής υγείας μαθητών και εκπαιδευτικών αποτελούν τα κύρια μέτρα πρόληψης των σχολικών ατυχημάτων [r=0,78, p<0,001]. Συμπεράσματα: Ατυχήματα συμβαίνουν αρκετά συχνά κατά τη διάρκεια της σχολικής ζωής κυρίως αυτά είναι συγκρούσεις μεταξύ των παιδιών, ρινορραγίες, πτώσεις, άσκηση επιθετικότητας, λόγω της μεγάλης ενεργητικότητας των παιδιών σε αυτές τις ηλικίες. Δεν υπάρχει σαφές νομικό πλαίσιο για την πρόληψη των ατυχημάτων και την αντιμετώπισή τους. Όμως η πληρέστερη ενημέρωση και ανάληψη πρωτοβουλιών από εκπαιδευτικούς και γονείς θα συμβάλλουν στην αντιμετώπιση και πρόληψή τους. Κομβικής σημασία είναι η τήρηση των προδιαγραφών κατασκευής και διαμόρφωσης των σχολικών χώρων αλλά και ο διορισμός σχολικών νοσηλευτών οι οποίοι θα συνεπικουρήσουν στην αποτροπή και διαχείριση των σχολικών ατυχημάτων.Introduction: School accidents in our country constitute a significant health problem. Morbidity Surveys for school accidents and safety of facilities in school environment are limited. Usually injuries recorded at school occur during breaks, and during gym training .The factor of physical activity is the most important on the risk of injury. Aim: The purpose of this research is to investigate the views and attitudes of teachers on accidents in primary schools. Sample - Methodology: The survey data was collected by 155 teachers in March 2019, using an anonymous quantitative questionnaire as a tool. Results: In total 120 women and 35 men teachers participated the study, with a mean age of 40.9 years stated history of at least 51% of accidents occurs during school day program. The findings show that accidents occur mainly in the courtyard of the school, on the corridors of the building and in the classrooms. The common accidents are conflicts between children, falls, aggression, bleeding, and injuries. Teachers, however, do not have the proper legal protection and authority to face a school accident. Regarding the type of school accidents, falls in conflicts 16,6%, bleeding and injuries 14,2%, slippery floor 12,2%, are the most common. Usually first aid is given within the school environment 39,3% and after that, parents are asked to take the student back home 38%. However, there are also more serious accidents, such as falls and injuries that require a student's transfer to hospital / health center or a call to the National Emergency Aid Centre for delivery and treatment. Finally, an important finding is that health education programs for all the involves, are the main measures to prevent school accidents [r = 0.78, p <0.001]. Conclusions: Accidents happen quite often during school life mostly falls, conflicts, bleeding and injurie . A legal framework for accident prevention and coping is needed. Also information and initiative for teachers, students, and parents, will help to cope and prevent them. It is crucial to comply with the specifications for the construction and configuration of school facilities, as well as the presence of school nurses who will assist in their prevention and treatment

Solitary Confinement and Criminogenic Attitudes: Is Isolation Reinforcing Pro-Criminal Thoughts, Feelings, and Beliefs?

Documented increases of problematic symptomatology following exposure to social exclusion contexts may be suggestive of increases in antisocial cognition and pro-criminal attitudes among prisoners. An exacerbation in behavioral indicators of criminality in correctional populations including aggressive behavior, reduced cooperation, and deficits in impulse control may suggest that restrictive and exclusionary correctional practices can aggravate criminogenic thoughts, feelings, or beliefs. Existing literature indicates that an endorsement of pro-criminal attitudes is one of the greatest predictors of future criminal behavior. The study will recruit 400 randomly selected female adult inmates from Florence McClure Women’s Correctional Facility of Las Vegas, Nevada. A hard copy of self-report survey will be given to the participants and is expected to take 1 hour to complete. After informed consent, participants will be asked to complete a survey regarding their demographics, confinement, and pro-criminal attitudes. Participants will be surveyed at the beginning of the study, and approximately 1 week after they are released from segregation. At least one participant from the initial sample who approximately matches the demographics of the participant who is exiting segregation will also be surveyed at the same time as part of a control group. The primary goal of this study is to demonstrate the negative effects of solitary confinement. The secondary goal is to impact policy in correctional institutions. This study aims to understand whether being placed in solitary confinement can affect pro-criminal attitudes. This research will become a strong premise to the argument of abolishing solitary confinement.https://digitalscholarship.unlv.edu/durep_posters/1032/thumbnail.jp

Reversal of Tetracycline Resistance by Cepharanthine, Cinchonidine, Ellagic Acid and Propyl Gallate in a Multi-drug Resistant Escherichia coli

Bacterial resistance to antibiotics is an increasing threat to global healthcare systems. We therefore sought compounds with potential to reverse antibiotic resistance in a clinically relevant multi-drug resistant isolate of Escherichia coli (NCTC 13400). 200 natural compounds with a history of either safe oral use in man, or as a component of a traditional herb or medicine, were screened. Four compounds; ellagic acid, propyl gallate, cinchonidine and cepharanthine, lowered the minimum inhibitory concentrations (MICs) of tetracycline, chloramphenicol and tobramycin by up to fourfold, and when combined up to eightfold. These compounds had no impact on the MICs of ampicillin, erythromycin or trimethoprim. Mechanistic studies revealed that while cepharanthine potently suppressed efflux of the marker Nile red from bacterial cells, the other hit compounds slowed cellular accumulation of this marker, and/or slowed bacterial growth in the absence of antibiotic. Although cepharanthine showed some toxicity in a cultured HEK-293 mammalian cell-line model, the other hit compounds exhibited no toxicity at concentrations where they are active against E. coli NCTC 13400. The results suggest that phytochemicals with capacity to reverse antibiotic resistance may be more common in traditional medicines than previously appreciated, and may offer useful scaffolds for the development of antibiotic-sensitising drugs

Antimicrobial resistance and synergy in herbal medicine

Antimicrobial resistance (AMR) is a serious and growing threat to human health. The development of new antibiotics is limited and slow. The tradition of synergy in herbal medicine is being used as a source of research ideas. A literature review of antimicrobial research and plant synergy published in a five year period was carried out using online databases. The in vitro findings were that most of the research reported synergy both within plants and between plants and antibiotics. Whole plant extracts and combinations of compounds were shown to be more effective antimicrobials than isolated constituents. The discussion highlights that the in vitro herbal research findings are difficult to apply to practice and aren’t progressing to clinical trials. Collaborative, innovative, inter-disciplinary clinical research is recommended

Clinical and laboratory features associated with macrophage activation syndrome in Still's disease: data from the international AIDA Network Still's Disease Registry

: To characterize clinical and laboratory signs of patients with still's disease experiencing macrophage activation syndrome (MAS) and identify factors associated with MAS development. patients with still's disease classified according to internationally accepted criteria were enrolled in the autoInflammatory disease alliance (AIDA) still's disease registry. clinical and laboratory features observed during the inflammatory attack complicated by MAS were included in univariate and multivariate logistic regression analysis to identify factors associated to MAS development. A total of 414 patients with Still's disease were included; 39 (9.4%) of them developed MAS during clinical history. At univariate analyses, the following variables were significantly associated with MAS: classification of arthritis based on the number of joints involved (p = 0.003), liver involvement (p = 0.04), hepatomegaly (p = 0.02), hepatic failure (p = 0.01), axillary lymphadenopathy (p = 0.04), pneumonia (p = 0.03), acute respiratory distress syndrome (p < 0.001), platelet abnormalities (p < 0.001), high serum ferritin levels (p = 0.009), abnormal liver function tests (p = 0.009), hypoalbuminemia (p = 0.002), increased LDH (p = 0.001), and LDH serum levels (p < 0.001). at multivariate analysis, hepatomegaly (OR 8.7, 95% CI 1.9-52.6, p = 0.007) and monoarthritis (OR 15.8, 95% CI 2.9-97.1, p = 0.001), were directly associated with MAS, while the decade of life at Still's disease onset (OR 0.6, 95% CI 0.4-0.9, p = 0.045), a normal platelet count (OR 0.1, 95% CI 0.01-0.8, p = 0.034) or thrombocytosis (OR 0.01, 95% CI 0.0-0.2, p = 0.008) resulted to be protective. clinical and laboratory factors associated with MAS development have been identified in a large cohort of patients based on real-life data

Clinical and laboratory features associated with macrophage activation syndrome in Still’s disease: data from the international AIDA Network Still’s Disease Registry

To characterize clinical and laboratory signs of patients with Still's disease experiencing macrophage activation syndrome (MAS) and identify factors associated with MAS development. Patients with Still's disease classified according to internationally accepted criteria were enrolled in the AutoInflammatory Disease Alliance (AIDA) Still's Disease Registry. Clinical and laboratory features observed during the inflammatory attack complicated by MAS were included in univariate and multivariate logistic regression analysis to identify factors associated to MAS development. A total of 414 patients with Still's disease were included; 39 (9.4%) of them developed MAS during clinical history. At univariate analyses, the following variables were significantly associated with MAS: classification of arthritis based on the number of joints involved (p = 0.003), liver involvement (p = 0.04), hepatomegaly (p = 0.02), hepatic failure (p = 0.01), axillary lymphadenopathy (p = 0.04), pneumonia (p = 0.03), acute respiratory distress syndrome (p < 0.001), platelet abnormalities (p < 0.001), high serum ferritin levels (p = 0.009), abnormal liver function tests (p = 0.009), hypoalbuminemia (p = 0.002), increased LDH (p = 0.001), and LDH serum levels (p < 0.001). At multivariate analysis, hepatomegaly (OR 8.7, 95% CI 1.9-52.6, p = 0.007) and monoarthritis (OR 15.8, 95% CI 2.9-97.1, p = 0.001), were directly associated with MAS, while the decade of life at Still's disease onset (OR 0.6, 95% CI 0.4-0.9, p = 0.045), a normal platelet count (OR 0.1, 95% CI 0.01-0.8, p = 0.034) or thrombocytosis (OR 0.01, 95% CI 0.0-0.2, p = 0.008) resulted to be protective. Clinical and laboratory factors associated with MAS development have been identified in a large cohort of patients based on real-life data. © 2023, The Author(s)

Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study

Background: Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods: The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings: We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8·0 years [IQR 4·2–11·4], 1191 [59·3%] male and 818 [40·7%] female, and 825 [41·1%] White). 680 (33·8%) patients received primary treatment with intravenous immunoglobulin, 698 (34·7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24·2%) with glucocorticoids alone; 59 (2·9%) patients received other combinations, including biologicals, and 85 (4·2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1·09 (95% CI 0·75–1·58; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids and 0·93 (0·58–1·47; corrected p value=1·00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1·04 (95% CI 0·91–1·20; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids, and 0·84 (0·70–1·00; corrected p value=0·22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0·15 [95% CI 0·11–0·20]; p<0·0001) and glucocorticoids alone (0·68 [0·50–0·93]; p=0·014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0·50 [95% CI 0·38–0·67]; p<0·0001) or glucocorticoids alone (0·63 [0·45–0·88]; p=0·0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation: Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding: Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health

Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study

Background Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8·0 years [IQR 4·2–11·4], 1191 [59·3%] male and 818 [40·7%] female, and 825 [41·1%] White). 680 (33·8%) patients received primary treatment with intravenous immunoglobulin, 698 (34·7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24·2%) with glucocorticoids alone; 59 (2·9%) patients received other combinations, including biologicals, and 85 (4·2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1·09 (95% CI 0·75–1·58; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids and 0·93 (0·58–1·47; corrected p value=1·00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1·04 (95% CI 0·91–1·20; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids, and 0·84 (0·70–1·00; corrected p value=0·22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0·15 [95% CI 0·11–0·20]; p<0·0001) and glucocorticoids alone (0·68 [0·50–0·93]; p=0·014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0·50 [95% CI 0·38–0·67]; p<0·0001) or glucocorticoids alone (0·63 [0·45–0·88]; p=0·0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health

Efficiency measurement and analysis of selected greek agricultural products: a robust nonparametric approach

The research aim of this dissertation is to examine the efficiency measure and analysis of selected products regarding the agricultural sector of Greece, emphasizing in the application and extension of recent methods of econometric estimation. It focuses on both estimating the technical efficiency of agricultural production units and examining the impact of environmental/exogenous factors on the efficiency. Extending the analysis, the dissertation also aims to measure the managerial efficiency of agricultural productive units and investigate it’s correlation with the technical efficiency. To our knowledge, regarding the estimation and the analysis of technical efficiency, in the present study is applied for the first time the combination of the nonparametric order-α efficiency estimator with mixed (discrete and continuous) environmental/exogenous variables. An additional originality, concerning the previous studies, is the implementation of a theoretically consistent way to incorporate time effects in modeling technical efficiency with robust nonparametric methods. Also the contribution in the assessment of managerial efficiency lies in combining a recently developed estimation approach with the robust nonparametric order-α estimator with mixed environmental factors. The development of ad-hoc software made feasible the utilization and extension of recently methods. The empirical analysis of the present study relies on data coming from the EU Farm Accounting Data Network and concerns two of the main products of the Greek agricultural sector namely, the cereals and the olive growing farms. The assessment of efficiency is a real research challenge for a variety of reasons: the objectives of the last reform of the Common Agricultural Policy, the international economic situations that encourage the competitive production, the viability of the Greek agricultural sector and the existing recession and financial crisis are some to name a few. In the dissertation’s context three time periods are empirically studied: for the cereal farms the year 2009, while for the olive growing farms the time periods 2006-2009 and 2008-2011. The empirical analysis for both the cereal farms for the year 2009 and the olive growing farms for the time period 2006-2009 indicates considerable technical efficiency differentials among the sample’s units. However, a large part of the technical efficiency differentials disappears once the environmental/exogenous factors are accounted for, while many of them have a statistically significant effect on efficiency. The study of the technical and managerial efficiency for olive growing farms concerning the time period 2008-2011 reveals the existence of a strong positive association between them. Also according to the empirical results the level of managerial efficiency has a significant association with certain environmental factors.Πεδίο έρευνας της παρούσας διατριβής αποτελεί η μέτρηση και ανάλυση της αποτελεσματικότητας επιλεγμένων προϊόντων του γεωργικού τομέα της Ελλάδας, με έμφαση στην εφαρμογή και επέκταση πρόσφατων μεθόδων οικονομετρικής εκτίμησης. Αρχικά, γίνεται εκτίμηση της τεχνικής αποτελεσματικότητας των γεωργικών εκμεταλλεύσεων και εν συνεχεία διερευνάται η επίδραση ενός αριθμού περιβαλλοντικών/εξωγενών μεταβλητών στην αποτελεσματικότητα. Επεκτείνοντας την ανάλυση, η διατριβή εστιάζει και στη μέτρηση της διοικητικής αποτελεσματικότητας των γεωργικών παραγωγικών μονάδων και στη διερεύνηση της συσχέτισής της με την τεχνική αποτελεσματικότητα. Στο πλαίσιο της εκτίμησης και ανάλυσης της τεχνικής αποτελεσματικότητας στην παρούσα διατριβή, από ό,τι είμαστε σε θέση να γνωρίζουμε, εφαρμόζεται για πρώτη φορά ο συνδυασμός του μη παραμετρικού τάξης α εκτιμητή της αποτελεσματικότητας με μεικτές (διακριτές και συνεχείς) περιβαλλοντικές/εξωγενείς μεταβλητές. Μια επιπρόσθετη πρωτοτυπία, σε σχέση με την προγενέστερη βιβλιογραφία, αποτελεί και η εφαρμογή μιας συνεπούς θεωρητικά προσέγγισης σε εύρωστο μη παραμετρικό πλαίσιο για την εισαγωγή της επίδρασης του χρόνου στην εξέλιξη της τεχνικής αποτελεσματικότητας. Επίσης η συμβολή της διατριβής στην αποτίμηση της διοικητικής αποτελεσματικότητας έγκειται στο συγκερασμό του εύρωστου μη παραμετρικού τάξης α εκτιμητή, με μεικτές περιβαλλοντικές μεταβλητές, με πρόσφατες μεθόδους εκτίμησης. Η ανάπτυξη του κατάλληλου λογισμικού κατέστησε εφικτή τη χρησιμοποίηση και επέκταση των προσφάτως εισαχθέντων μεθοδολογιών της διεθνούς βιβλιογραφίας. Τα δεδομένα που χρησιμοποιούνται στην παρούσα διατριβή προέρχονται από το Δίκτυο Γεωργικής Λογιστικής Πληροφόρησης της Ευρωπαϊκής Επιτροπής και αφορούν δύο από τα κυριότερα προϊόντα του γεωργικού τομέα της Ελλάδας, τα σιτηρά και την καλλιέργεια ελαιόδεντρων. Οι λόγοι που καθιστούν τη μελέτη της αποτελεσματικότητας μια πραγματική ερευνητική πρόκληση είναι πολλοί: οι στόχοι της τελευταίας αναθεώρησης της Κοινής Γεωργικής Πολιτικής, οι διεθνείς συγκυρίες που ευνοούν την ανταγωνιστική παραγωγή, η βιωσιμότητα του ελληνικού γεωργικού τομέα και η υφιστάμενη ύφεση και δημοσιονομική κρίση συγκαταλέγονται σ’ αυτούς. Στο πλαίσιο της διατριβής μελετώνται εμπειρικά τρεις χρονικές περίοδοι: για τα σιτηρά, ένα συγκεκριμένο έτος, το 2009, για τις ελαιοκομικές εκμεταλλεύσεις οι περίοδοι 2006-2009 και 2008-2011. Η εμπειρική ανάλυση τόσο της παραγωγής σιτηρών στο έτος 2009 όσο και της παραγωγής ελαιοκομικών προϊόντων για τη χρονική περίοδο 2006-2009 έδειξε ότι υπάρχουν σημαντικές διαφοροποιήσεις στην τεχνική αποτελεσματικότητα των εκμεταλλεύσεων του δείγματος. Σημαντικό τμήμα της διαφοροποίησης ωστόσο εξαλείφεται όταν ληφθεί υπόψη μια σειρά περιβαλλοντικών/εξωγενών παραγόντων, αρκετοί εκ των οποίων εμφανίζονται να έχουν στατιστικά σημαντική επίδραση στην αποτελεσματικότητα. Από τη μελέτη της τεχνικής και της διοικητικής αποτελεσματικότητας των εκμεταλλεύσεων καλλιέργειας ελαιόδεντρων για τη χρονική περίοδο 2008-2011 διαπιστώθηκε η ύπαρξη ισχυρής θετικής συσχέτισης μεταξύ τους. Τα αποτελέσματα έδειξαν επίσης ότι υφίσταται συσχέτιση μεταξύ της διοικητικής αποτελεσματικότητας και ορισμένων περιβαλλοντικών παραγόντων