144 research outputs found
Developing and validating a measure of the strength of the HRM system: Operationalizing the construct and relationships among its dimensions
The four studies in this article introduce a questionnaire to measure Strength of the HRM System (HRMSQ), a multidimensional construct, theoretically developed by Bowen and Ostroff (2004). Strength of the HRM System is a set of process characteristics that lead to effectiveness in conveying signals to employees that allow them to create a shared meaning of desired and appropriate work behaviours. Nine characteristics are suggested, grouped in three features: Distinctiveness, Consistency and Consensus. Study 1 developed and tested a questionnaire in a sample of workers from five different sectors. Study 2 cross-validated the measure in a sample of civil servants in a municipality. These two studies used performance appraisal as the reference HRM practice and led to a short version of the HRMSQ. Study 3 and Study 4 extend the HRMSQ to several common HRM practices. The HRMSQ is tested in two samples, of call center and several private and public organizations‟ workers (study 3). In study 4 the questionnaire is refined and tested with a sample from a hotel chain and finally cross-validated with two other samples, in the insurance and batteries sectors, leading to a longer version of the HRMSQ. Content analysis of several interviews with human resource managers and the Rasch model (1960, 1961, 1980), were used to define and select the indicators of the questionnaire. Convergent, discriminant and predictive validity of the measure are tested. The results of the four studies highlight the complexity of the relationships between the proposed characteristics and support the validity of a parsimonious measure of Strength of the HRM System.Research grant by Fundação para a Ciência e Tecnologi
miR-335 targets LRRK2 and mitigates inflammation in Parkinson’s disease
Copyright © 2021 Oliveira, Dionísio, Gaspar, Correia Guedes, Coelho, Rosa, Ferreira, Amaral and Rodrigues. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Parkinson's disease (PD) is mainly driven by dopaminergic neuronal degeneration in the substantia nigra pars compacta accompanied by chronic neuroinflammation. Despite being mainly sporadic, approximately 10% of all cases are defined as heritable forms of PD, with mutations in the leucine-rich repeat kinase (LRRK2) gene being the most frequent known cause of familial PD. MicroRNAs (miRNAs or miRs), including miR-335, are frequently deregulated in neurodegenerative diseases, such as PD. Here, we aimed to dissect the protective role of miR-335 during inflammation and/or neurodegenerative events in experimental models of PD. Our results showed that miR-335 is significantly downregulated in different PD-mimicking conditions, including BV2 microglia cells stimulated with lipopolysaccharide (LPS) and/or overexpressing wild-type LRRK2. Importantly, these results were confirmed in serum of mice injected with 1-methyl-1-4-phenyl-1,2,3,6-tetrahydripyridine hydrochloride (MPTP), and further validated in patients with idiopathic PD (iPD) and those harboring mutations in LRRK2 (LRRK2-PD), thus corroborating potential clinical relevance. Mechanistically, miR-335 directly targeted LRRK2 mRNA. In the BV2 and N9 microglia cell lines, miR-335 strongly counteracted LPS-induced proinflammatory gene expression, and downregulated receptor interacting protein 1 (RIP1) and RIP3, two important players of necroptotic and inflammatory signaling pathways. Further, miR-335 inhibited LPS-mediated ERK1/2 activation. LRRK2-Wt-induced proinflammatory gene expression was also significantly reduced by miR-335 overexpression. Finally, in SH-SY5Y neuroblastoma cells, miR-335 decreased the expression of pro-inflammatory genes triggered by α-synuclein. In conclusion, we revealed novel roles for miR-335 in both microglia and neuronal cells that strongly halt the effects of classical inflammatory stimuli or LRRK2-Wt overexpression, thus attenuating chronic neuroinflammation.This research was funded in part by UIDB/04138/2020 from Fundação para a Ciência e Tecnologia (FCT), Portugal. SO received a Ph.D. fellowship (PD/BD/128332/2017) from FCT.info:eu-repo/semantics/publishedVersio
Flutuação populacional de pragas e predadores em citros
This study was carried out in a 5.000 m2 area at Piracicaba, SP, Brazil, to determine the behavior of the pest and predator insects in citrus. A portable vacuum collector AS-ESALQ modal as used. Weekly, samples were taken at rondom from the top of ten plants, 20 times per plant. Two species - Aleurothrixus floccosus (Maskell 1896) and Toxoptera citricidus (Kirk 1907) - were the only Coleoptera pests found. They occurred through all the year, having higher frequencies in April and November. The predators from file Coleoptera were: Cycloneda sanguinea (Linné 1763). Nephaspis sp., Scymnus sp, and Stethorus sp. Three species of Neuroptera were found: Chrysopa sp., Megalomus sp., and Hemerobius sp., that have population peaks in January, August and December. One Diptera species was found as of importance: Micrempis sp., which presented four peaks, in the months January, April, August and October.Experimento efetuado numa área de citros, de 5.000 m2, em Piracicaba, SP, para determinar o comportamento dos insetos-pragas e insetos-predadores, em citros. Foi usado um coletor de sucção, portátil, modelo AS-ESALQ. Semanalmente, em 1977, as coletas foram feitas ao acaso, de dez plantas, por sucção do aparelho, em número de 20, ao redor da copa de cada árvore. Duas espécies revelaram-se pragas: Aleurothrixus floccosus (Maskell 1896) e Toxoptera citricidus (Kirk 1907). Foram as únicas pragas da ordem Homoptera. Ambos ocorreram durante o ano inteiro, apresentando dois picos populacionais: um, em abril, e outro, em novembro. Entre os coleópteros, houve quatro espécies de predadores: Cycloneda sanguinea (Linné 1763), Nephaspis sp, Scymnus sp., e Stethorus sp.; e entre os neurópteros, as três espécies: Chrysopa sp., Megalomus sp. e Hemerobius sp., que apresentaram picos populacionais em janeiro, agosto e dezembro. Entre os dípteros, foi observada apenas uma espécie de notável importância, e que apresentou quatro picos - a saber, em janeiro, abril, agosto e outubro -: É a Micrempis sp
Substantia nigra neuromelanin as an imaging biomarker of disease progression in Parkinson’s Disease
"BACKGROUND:
A specific T1-weighted magnetic resonance imaging (MRI) sequence has been shown to detect substantia nigra (SN) neuromelanin (NM) signal changes that accurately discriminate Parkinson's disease (PD) patients from controls, even in early disease stages. However, it is unclear what happens to these SN changes in later disease stages and if they can be a marker of disease progression.
OBJECTIVE:
to investigate the pattern of SN-NM area loss and contrast ratio (CR) intensity changes in late-stage PD (LSPD) compared to earlier disease stages.
METHODS:
A comparative cross-sectional study was performed, analyzing SN-NM MRI signal in LSPD (Schwab and England Activities of Daily Living Scale score 3), comparing this group with de novo, 2-5 year PD and controls. SN-NM signal area and CR values for the internal and lateral SN regions were obtained with semi-automated methods.
RESULTS:
13 LSPD, 12 de novo patients with PD, 10 PD patients with a 2-5 year disease duration, and 10 controls were included. NM signal area was significantly decreased in LSPD compared to de novo PD (P-value = 0.005; sensitivity: 75%; specificity 92% and AUC: 0.86). In the lateral SN region, a decrease in the CR was detected in all PD groups compared to controls; despite not reaching statistical significance, a slight increment was observed comparing LSPD to 2-5 year PD. NM signal area significantly correlated with HY (R = -0.37; P < 0.05) and Movement disorder Society Unified Parkinson's Disease Rating Scale part II (MDS-UPDRS) (R = -0.4; P < 0.05) while a weak correlation was found with MDS-UPDRS part III (R = -0.26; P: 0.1).
CONCLUSION:
SN area evaluated by NM-sensitive MRI may be a promising biomarker of nigral degeneration and disease progression in PD patients."info:eu-repo/semantics/publishedVersio
Substantia nigra area evaluated by neuromelanin-sensitive MRI as an imaging biomarker of disease progression in Parkinson's disease
Poster presented at the International Congress of Parkinson's Disease and Movement Disorders. 4-8 June 2017, Vancouver, CanadaN/
Gene expression differences in peripheral blood of Parkinson's disease patients with distinct progression profiles
The prognosis of neurodegenerative disorders is clinically challenging due to the inexistence of established biomarkers for predicting disease progression. Here, we performed an exploratory cross-sectional, case-control study aimed at determining whether gene expression differences in peripheral blood may be used as a signature of Parkinson's disease (PD) progression, thereby shedding light into potential molecular mechanisms underlying disease development. We compared transcriptional profiles in the blood from 34 PD patients who developed postural instability within ten years with those of 33 patients who did not develop postural instability within this time frame. Our study identified >200 differentially expressed genes between the two groups. The expression of several of the genes identified was previously found deregulated in animal models of PD and in PD patients. Relevant genes were selected for validation by real-time PCR in a subset of patients. The genes validated were linked to nucleic acid metabolism, mitochondria, immune response and intracellular-transport. Interestingly, we also found deregulation of these genes in a dopaminergic cell model of PD, a simple paradigm that can now be used to further dissect the role of these molecular players on dopaminergic cell loss. Altogether, our study provides preliminary evidence that expression changes in specific groups of genes and pathways, detected in peripheral blood samples, may be correlated with differential PD progression. Our exploratory study suggests that peripheral gene expression profiling may prove valuable for assisting in prediction of PD prognosis, and identifies novel culprits possibly involved in dopaminergic cell death. Given the exploratory nature of our study, further investigations using independent, well-characterized cohorts will be essential in order to validate our candidates as predictors of PD prognosis and to definitively confirm the value of gene expression analysis in aiding patient stratification and therapeutic intervention
Morphological analysis and description of the ovaries of female silky sharks, Carcharhinus falciformis (Müller & Henle, 1839)
This work aims to study the female reproductive tract of silky sharks, Carcharhinus falciformis, captured in the South and
Equatorial Atlantic Ocean. Samples were collected between January 2008 and March 2010 through oceanic commercial vessels
that targeted tuna and swordfish, with a total of 17 females collected. The methodologies followed for analyzing the ovaries
of those females included both macroscopic and histological analysis. Macroscopically, it was possible to determine that the
ovaries on these sharks is suspended by mesenteries in the anterior section of the body cavity, heavily irrigated by blood
vessels, and contains a wide range of oocytes. Ovaries were found in three distinct maturational stages: Stage I (Immature),
Stage II (Maturing) and Stage III (Mature). Immature ovaries were small, with widths ranging from 1.0 to 3.1 cm, and had a
gelatinous or granulose internal structure; maturing ovaries were slightly larger, ranging in width between 5.2 and 6.0 cm;
mature ovaries ranged in width between 6.5 and 7.8 cm, and had a more rounded shape and the presence of large and well
developed oocytes. Under microscopic examination, it was observed that the ovaries were covered with simple epithelial
tissue during the early development stages and a simple cubic epithelium in the final stages of maturation. During the initial
maturation stages the epigonal organ was not differentiated from the ovary. In mature specimens, the ovary showed a simple
cubic epithelium and just below this epithelium there was a layer of dense connective tissue and muscle with the presence of
vitellogenic oocytes and fat cells. A thin yolk membrane enclosing the oocytes was also evident. Finally, it was possible to
distinguish a zona pellucida, separating the oocytes from the follicle wall and a basal lamina between the granular layers and
the teak layer.info:eu-repo/semantics/publishedVersio
Avaliação de um sistema de monitorização portátil do retorno anestésico baseado em análise de movimento em caninos e felinos / Evaluation of a portable anesthetic return monitoring system based on canine and feline movement analysis
O monitoramento do retorno anestésico em pequenos animais pode ser desafiador. Este trabalho visou validar a monitorização portátil do retorno anestésico por meio de um sistema BITalino R-IoT conectado a um computador via Wi-Fi, baseado na análise de movimento e aquisição digital de sinais vitais em pequenos animais. O movimento foi medido com base na variação da aceleração em intervalos de cinco milisegundos em cada eixo, sendo então somados os três eixos. Foram avaliadas 12 fêmeas, caninas e felinas, sem raças definidas, com idade estimada entre 6 meses a 3 anos e consideradas ASA I. Os animais foram alocados em 2 grupos,sendo todos submetidos a cirurgia de ovário histerectomia sob o mesmo protocolo anestésico. Os indivíduos foram monitorados durante 1 minuto, por meio do acoplamento do aparelho ao pescoço, em 5 momentos diferentes: com o animal livre de fármacos (M1), 15 minutos após a medicação pré anestésica (M2), na extubação (M3), 30 minutos pós extubação (M4) e, por fim, 120 minutos pós extubação (M5). Após o procedimento foram calculadas as médias dos valores coletados. Observou-se que todos animais iniciaram M1 com 662 pontos e retornaram totalmente à normalidade em M5, com diferença entre os grupos de M2 a M4. Os felinos apresentaram maior depressão e excitação do que os caninos. O valores mais baixos observam-se em M3, aumentado a excitação até M4, com retorno aos valores iniciais em M5. Os estudo deste parâmetros sugere a futura capacidade de utilizar desta tecnologia para identificar ataques convulsivos. Os dados obtidos demonstraram a capacidade do aparelho BITalino em detectar as variações, mesmo que pequenas, na movimentação e sinais vitais dos animais em questão; além de ser de fácil montagem e aplicação na rotina cirúrgica. A ferramenta aqui apresentada permite o acompanhamento seguro dos animais no contexto perioperatório e de internamento, aumentando a eficiência e produtividade dos centros de atendimento veterinários, além de auxiliar na diminuição dos custos envolvidos em certos procedimentos
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