1,501 research outputs found
Correcting adjacent errors using permutation code trees
Abcstact: Permutation codes are M-ary codes which can be used, in combination with M-ary FSK, to correct errors in Power Line Communications (PLC). It has been shown in [1] that permutation code trees can be used to correct a single substitution or synchronization error per codeword, without the use of markers. In this paper, we show that, due to the structure of the permutation code tree, adjacent errors can also be corrected if the codebook is adapted
Combined permutation codes for synchronization
Abstract: A combined code is a code that combines two or more characteristics of other codes. A construction is presented in this paper of permutation codes that are self-synchronizing and able to correct a number of deletion errors per codeword, thus a combined permutation code. Synchronization errors, modelled as deletion(s) and/or insertion(s) of bits or symbols, can be catastrophic if not detected and corrected. Some classes of codes have been proposed that are synchronizable, i.e. they can be used to regain synchronization although the error leading to the loss of synchronization is not corrected. Typically, different classes of codes are needed to correct deletion and/or insertion errors after codeword boundaries have been detected. The codebooks presented in this paper consist of codewords divided into segments. By imposing restrictions on the segments, the codewords are synchronizable. One deletion error can be detected and corrected per segment
Sexual and marital trajectories and HIV infection among ever-married women in rural Malawi.
OBJECTIVE: To explore how sexual and marital trajectories are associated with HIV infection among ever-married women in rural Malawi. METHODS: Retrospective survey data and HIV biomarker data for 926 ever-married women interviewed in the Malawi Diffusion and Ideational Change Project were used. The associations between HIV infection and four key life course transitions considered individually (age at sexual debut, premarital sexual activity, entry into marriage and marital disruption by divorce or death) were examined. These transitions were then sequenced to construct trajectories that represent the variety of patterns in the data. The association between different trajectories and HIV prevalence was examined, controlling for potentially confounding factors such as age and region. RESULTS: Although each life course transition taken in isolation may be associated with HIV infection, their combined effect appeared to be conditional on the sequence in which they occurred. Although early sexual debut, not marrying one's first sexual partner and having a disrupted marriage each increased the likelihood of HIV infection, their risk was not additive. Women who both delayed sexual debut and did not marry their first partner are, once married, more likely to experience marital disruption and to be HIV-positive. Women who marry their first partner but who have sex at a young age, however, are also at considerable risk. CONCLUSIONS: These findings identify the potential of a life course perspective for understanding why some women become infected with HIV and others do not, as well as the differentials in HIV prevalence that originate from the sequence of sexual and marital transitions in one's life. The analysis suggests, however, the need for further data collection to permit a better examination of the mechanisms that account for variations in life course trajectories and thus in lifetime probabilities of HIV infection
Determinants of Length of Stay After Vaginal Deliveries in the Friuli Venezia Giulia Region (NorthEastern Italy), 2005\u20132015
Although length of stay (LoS) after childbirth has been diminishing in several high-income countries
in recent decades, the evidence on the impact of early discharge (ED) on healthy mothers and term
newborns after vaginal deliveries (VD) is still inconclusive and little is known on the characteristics
of those discharged early. We conducted a population-based study in Friuli Venezia Giulia (FVG)
during 2005\u20132015, to investigate the mean LoS and the percentage of LoS longer than our proposed
ED benchmarks following VD: 2 days after spontaneous vaginal deliveries (SVD) and 3 days post
instrumental vaginal deliveries (IVD). We employed a multivariable logistic as well as a linear regression
model, adjusting for a considerable number of factors pertaining to health-care setting and timeframe,
maternal health factors, newborn clinical factors, obstetric history factors, socio-demographic
background and present obstetric conditions. Results were expressed as odds ratios (OR) and regression
coefcients (RC) with 95% confdence interval (95%CI). The adjusted mean LoS was calculated by level
of pregnancy risk (high vs. low). Due to a very high number of multiple tests performed we employed
the procedure proposed by Benjamini-Hochberg (BH) as a further selection criterion to calculate the BH
p-value for the respective estimates. During 2005\u20132015, the average LoS in FVG was 2.9 and 3.3 days
after SVD and IVD respectively, and the pooled regional proportion of LoS>ED was 64.4% for SVD
and 32.0% for IVD. The variation of LoS across calendar years was marginal for both vaginal delivery
modes (VDM). The adjusted mean LoS was higher in IVD than SVD, and although a decline of LoS>\u2009ED
and mean LoS over time was observed for both VDM, there was little variation of the adjusted mean
LoS by nationality of the woman and by level of pregnancy risk (high vs. low). By contrast, the adjusted
fgures for hospitals with shortest (centres A and G) and longest (centre B) mean LoS were 2.3 and 3.4
days respectively, among \u201clow risk\u201d pregnancies. The corresponding fgures for \u201chigh risk\u201d pregnancies
were 2.5 days for centre A/G and 3.6 days for centre B. Therefore, the shift from \u201clow\u201d to \u201chigh\u201d risk
pregnancies in all three latter centres (A, B and G) increased the mean adjusted LoS just by 0.2 days.
By contrast, the discrepancy between maternity centres with highest and lowest adjusted mean LoS
post SVD (hospital B vs. A/G) was 1.1 days both among \u201clow risk\u201d (1.1 = 3.4\u20132.3 days) and \u201chigh risk\u201d
(1.1 = 3.6\u20132.5) pregnanices. Similar patterns were obseved also for IVD. Our adjusted regression models
confrmed that maternity centres were the main explanatory factor for LoS after childbirth in both VDM.
Therefore, health and clinical factors were less infuential than practice patterns in determining LoS
after VD. Hospitalization and discharge policies following childbirth in FVG should follow standardized
guidelines, to be enforced at hospital level. Any prolonged LoS post VD (LoS>\u2009ED) should be reviewed
and audited if need be. Primary care services within the catchment areas of the maternity centres
of FVG should be improved to implement the follow up of puerperae undergoing ED after VD.
At the beginning of the 20th century home births were the norm and hospital deliveries very rare. Women started to deliver in hospital during World War 2 (WW2), in facilities near the military areas where their respective partners were training. Tis trend continued in the decades following WW2, with standard length of stay afer childbirth (LoS) increasing up to 10 days.
In the 70 ies some USA hospitals started to assess the health of mothers and newborn for eligibility to returnhome within 12\u201324 hours afer childbirth, with a midwife on call for domiciliary care up to 3 days for 2 weekspost discharge.
In 1992 the American Academy of Pediatrics (AAP) and the American College of Obstetricians and
Gynecologists (ACOG) formalized the most frequently shared defnition of early discharge (ED) afer childbirth worldwide as a LoS less than 48 h post spontaneous vaginal deliveries (SVD) and less than 96 h post cesarean section (CS). Tereafer the reduction of LoS expanded to other high-income countries, with increasing applications of ED.
LoS afer childbirth remained however a controversial aspect of obstetric care, creating an open debate not
only on its impact on the health of mothers and babies but also on health policies, state legislations and functioning of the respective health care systems. Nevertheless, ED of mothers and newborn has in fact increased dramatically in several high-income countries over the past 10\u201315 years. However, the evidence on the impact of ED on healthy mothers and term newborns ( 6537 weeks) afer a vaginal delivery (VD) is still inconclusive and little is known of the characteristics of those discharged early.
Since LoS has become a critical indicator of efciency of health care delivery, understanding its associated
factors could provide information helpful in the reduction of health care costs, improvement in the delivery
of obstetric care, containment of untoward events associated with comorbidities and complications requiring readmission. For instance, in Canada (excluding Quebec) from 2003 to 2010, neonatal readmission rates were lowest for LoS of 1\u20132 days following VD and 2\u20134 days afer CS.
Several factors are reportedly associated with LoS in the open literature, including readiness for discharge
(clinical and perceived) of the mother8,17\u201319. However, information on the impact of medical/obstetrical conditions associated with pregnancies is scarce or totally lacking.
Using a comprehensive database with information on a considerable number of factors, we previously
reviewed the case mix of hospital performance by LoS post SVD as well as instrumental vaginal deliveries (IVD) during 2005\u20132015 in Friuli Venezia Giulia (FVG), a region of North-Eastern Italy.
In this study we present the impact of the outstanding determinants on LoS following SVD and IVD, with the aim of inforing health care policy makers
Concatenated permutation block codes based on set partitioning for substitution and deletion error-control
A new class of permutation codes is presented where, instead of considering one permutation as a codeword, codewords consist of a sequence of permutations. The advantage of using permutations, i.e. their favourable symbol diversity properties, is preserved. Additionally, using sequences of permutations as codewords, code rates close to the optimum rate can be achieved. Firstly, the complete set of permutations is divided into subsets by using set partitioning. Binary data is then mapped to permutations from these subsets. These permutations, together with a parity permutation, will form the codeword. Two constructions will be presented: one capable of detecting and correcting substitution errors and the other capable of detecting and correcting either substitution or deletion errors
Understanding Factors Leading to Primary Cesarean Section and Vaginal Birth After Cesarean Delivery in the Friuli-Venezia Giulia Region (North-Eastern Italy), 2005\u20132015
Although there is no evidence that elevated rates of cesarean sections (CS) translate into reduced maternal/child perinatal morbidity or mortality, CS have been increasingly overused almost everywhere, both in high and low-income countries. The primary cesarean section (PC S) has become
a major driver of the overall CS (OCS) rate, since it carries intrinsic risk of repeat CS (RCS) in future pregnancies. In our study we examined patterns of PCS, pl compared with planned TO LAC anned PCS (PPCS), vaginal birth after 1 previous CS (VBAC-1) and associated factors in Friuli Venezia Giulia
(FVG), a region of North-Eastern Italy, collecting data from its 11 maternity centres (coded from A to K) during 2005\u20132015. By fitting three multiple logistic regression models (one for each delivery mode), we calculated the adjusted rates of PCS and PPCS among women without history of CS, whilst the
calculation of the VBAC rate was restricted to women with just one previous CS (VBAC-1). Results, expressed as odds ratio (OR) with 95% confidence interval (95%CI), were controlled for the effect of hospital, calendar year as well as several factors related to the clinical and obstetric conditions of the
mothers and the newborn, the obstetric history and socio-demographic background. In FVG during 2005\u20132015 there were 24,467 OCS (rate of 24.2%), 19,565 PCS (19.6%), 7,736 PPCS (7.7%) and 2,303 VBAC-1 (28.4%). We found high variability of delivery mode (DM) at hospital level, especially for
PCS and PPCS. Breech presentation was the strongest determinant for PCS as well as PPCS. Leaving aside placenta previa/abuptio placenta/ante-partum hemorrhage, further significant factors, more importantly associated with PCS than PPCS were non-reassuring fetal status and obstructed labour,
followed by (in order of statistical significance): multiple birth; eclampsia/pre-eclampsia; maternal age 40\u201344 years; placental weight 600-99 g; oligohydramios; pre-delivery LoS 3\u20135 days; maternal age 35\u201339 years; placenta weight 1,000\u20131,500 g; birthweight < 2,000 g; maternal age 65 45 years; pre-delivery
LoS 65 6 days; mother\u2019s age 30\u201334 years; low birthweight (2,000\u20132,500 g); polyhydramnions; cord prolaspe; 656 US scas performed during pregnancy and pre-term gestations (33\u201336 weeks). Significant factors for PPCS were (in order of statistical significance): breech presentation; placenta previa/abruptio
placenta/ante-partum haemorrhage; multiple birth; pre-delivery LoS 65 3 days; placental weight 65 600 g; maternal age 40\u201344 years; 656 US scans performed in pregnancy; maternal age 65 45 and 35\u201339 years; oligohydramnios; eclampsia/pre-eclampsia; mother\u2019s age 30\u201334 years; birthweight
<2,000 g; polyhydramnios and pre-term gestation (33\u201336 weeks). VBAC-1 were more likely with gestation 65 41 weeks, placental weight <500 g and especially labour analgesia. During 2005\u20132015 the overall rate of PCS in FVG (19.6%) was substantially lower than the corresponding figure reported in
2010 for the entire Italy (29%) and still slightly under the most recent national PCS rate for 2017 (22.2%). The VBAC-1 rate on women with history of one previous CS in FVG was 28.4% (25.3% considering VBAC on all women with at least 1 previous CS), roughly three times the Italian national rate of 9% reported
for 2017. The discrepancy between the OCS rate at country level (38.1%) and FVG\u2019s (24.2%) is therefore mainly attributable to RCS. Although there was a marginal decrease of PCS and PPCS crudes rates over time in the whole region, accompained by a progressive enhancement of the crude VBAC rate, we found
remarkable variability of DM across hospitals. To further contain the number of unnecessary PCS and promote VBAC where appropriate, standardized obstetric protocols should be introduced and enforced at hospital level. Decision-making on PCS should be carefully scrutinized, introducing a diagnostic
second opinion for all PCS, particularly for term singleton pregancies with cephalic presentation and in case of obstructed labour as well as non-reassuring fetal status, grey areas potentially affected by subjective clinical assessment. This process of change could be facilitated with education of staff/
patients by opinion leaders and prenatal counseling for women and partners, although clinical audits, financial penalties and rewards to efficient maternity centres could also be considered
HIV/AIDS, declining family resources and the community safety net
Families play central roles in the HIV/AIDS pandemic, caring for both orphaned children and the ill. This extra caregiving depletes two family resources essential for supporting children: time and money. We use recent data from published studies in sub-Saharan Africa to illustrate deficits and document community responses. In Botswana, parents caring for the chronically ill had less time for their preschool children (74 versus 96 hours per month) and were almost twice as likely to leave children home alone (53% versus 27%); these children experienced greater health and academic problems. Caregiving often prevented adults from working full time or earning their previous level of income; 47% of orphan caregivers and 64% of HIV/AIDS caregivers reported financial difficulties due to caregiving. Communities can play an important role in helping families provide adequate childcare and financial support. Unfortunately, while communities commonly offer informal assistance, the value of such support is not adequate to match the magnitude of need: 75% of children's families in Malawi received assistance from their social network, but averaging only US$81 annually. We suggest communities can strengthen the capacity of families by implementing affordable quality childcare for 0–6 year olds, after-school programming for older children and youth, supportive care for ill children and parents, microlending to enhance earnings, training to increase access to quality jobs, decent working conditions, social insurance for the informal sector, and income and food transfers when families are unable to make ends meet
Sexual and marital trajectories and HIV infection among ever-married women in rural Malawi
OBJECTIVE: To explore how sexual and marital trajectories are associated with HIV infection among ever-married women in rural Malawi. METHODS: Retrospective survey data and HIV biomarker data for 926 ever-married women interviewed in the Malawi Diffusion and Ideational Change Project were used. The associations between HIV infection and four key life course transitions considered individually (age at sexual debut, premarital sexual activity, entry into marriage and marital disruption by divorce or death) were examined. These transitions were then sequenced to construct trajectories that represent the variety of patterns in the data. The association between different trajectories and HIV prevalence was examined, controlling for potentially confounding factors such as age and region. RESULTS: Although each life course transition taken in isolation may be associated with HIV infection, their combined effect appeared to be conditional on the sequence in which they occurred. Although early sexual debut, not marrying one's first sexual partner and having a disrupted marriage each increased the likelihood of HIV infection, their risk was not additive. Women who both delayed sexual debut and did not marry their first partner are, once married, more likely to experience marital disruption and to be HIV-positive. Women who marry their first partner but who have sex at a young age, however, are also at considerable risk. CONCLUSIONS: These findings identify the potential of a life course perspective for understanding why some women become infected with HIV and others do not, as well as the differentials in HIV prevalence that originate from the sequence of sexual and marital transitions in one's life. The analysis suggests, however, the need for further data collection to permit a better examination of the mechanisms that account for variations in life course trajectories and thus in lifetime probabilities of HIV infection
Global services and support for children with developmental delays and disabilities: Bridging research and policy gaps
Summary: 1. The United Nations Sustainable Development Goals and the UN Convention on the Rights of the Child (CRC) envision an inclusive society in which health and education contribute to the well-being of all. To achieve this vision, children with developmental delays and behavioral, cognitive, mental, and neurological disabilities need greater access to health care, early childhood care and development services, and education.
2. Improved population-level detection, alongside screening, assessment, and linkage to evidence-based, intersectoral services in the first years of life, can help maximize capabilities and increase the chances of social inclusion for children with developmental delays and disabilities.
3. Educational programs for children with delays and disabilities whose service delivery structure supports the ability of parents to work should be encouraged so that parents can participate in achieving children’s educational goals while also meeting their financial needs.
4. Parents and caregivers who receive training in psychosocial interventions and ongoing support can help children with delays and disabilities thrive in family contexts.
5. Family mental health influences the developmental trajectory of children. Ensuring that parents and caregivers have access to affordable, quality mental health services helps to prevent poor outcomes for children.
6. Rigorous evaluation, continuous quality improvement, and regular monitoring of the programmatic outcomes of services and policy approaches targeting children and caregivers would inform their implementation and serve to disseminate lessons learned from successful policy and program implementation
Recent Advances in Electron Cryotomography and their Application to Imaging Purified Protein Complexes, Isolated Organelles, and Small Cells
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