4,173 research outputs found

    Mutations in pericentrin cause Seckel syndrome with defective ATR-dependent DNA damage signaling

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    Large brain size is one of the defining characteristics of modern humans. Seckel syndrome (MIM 210600), a disorder of markedly reduced brain and body size, is associated with defective ATR-dependent DNA damage signaling. Only a single hypomorphic mutation of ATR has been identified in this genetically heterogeneous condition. We now report that mutations in the gene encoding pericentrin (PCNT)--resulting in the loss of pericentrin from the centrosome, where it has key functions anchoring both structural and regulatory proteins--also cause Seckel syndrome. Furthermore, we find that cells of individuals with Seckel syndrome due to mutations in PCNT (PCNT-Seckel) have defects in ATR-dependent checkpoint signaling, providing the first evidence linking a structural centrosomal protein with DNA damage signaling. These findings also suggest that other known microcephaly genes implicated in either DNA repair responses or centrosomal function may act in common developmental pathways determining human brain and body size

    MATERIALISM AND UAE NATIONALS

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    Amongst examined populations, research has found materialistic values to be empirically associated with lower levels of life satisfaction. While the causes of materialistic values are plentiful, extant research suggests that a primary driver is the rapid urbanization and commercialization of a society, with youth being more susceptible. The dramatic transformation of the UAE over the past four decades, coupled with the relatively young population, increases the likelihood that materialistic values have been cultivated among the population. This study sheds light on the interesting but under researched case of materialism in the UAE. A self-report survey measured the materialism and life satisfaction levels of 210 UAE residents (80 nationals and 130 non-nationals). Materialistic values were found to be negatively correlated with life satisfaction amongst our sample. In addition, UAE nationals reported significantly higher levels of materialism than non-national residents. To uncover the causes and consequences of high levels of materialism amongst UAE nationals, four focus groups and 25 in-depth interviews were conducted. Five major consequences of materialistic values were revealed: 1) the development of an increasingly competitive and narcissistic society, 2) the development of a more judgmental and less accepting society, 3) the use of consumption as a tool to boost confidence and self-esteem, 4) an increase in family conflicts and the delaying of marriage, and 5) a lack of savings and an increase in debt. The primary causes of materialistic values were: 1) the rapid development and commercialization of the UAE, 2) the consequences of materialism propagating the values in a self-perpetuating cycle, 3) narcissism and competition on social media, 4) Emirati values of generosity, hospitality, perfection and pride, and 5) parenting and youths lack of financial responsibilities. To advance life satisfaction levels within the UAE population, we propose that policy makers implement awareness campaigns, educational programs, and legislation to reduce the current levels of materialism

    Competition and habitat quality influence age and sex distribution in wintering rusty blackbirds.

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    Bird habitat quality is often inferred from species abundance measures during the breeding and non-breeding season and used for conservation management decisions. However, during the non-breeding season age and sex classes often occupy different habitats which suggest a need for more habitat-specific data. Rusty Blackbird (Euphagus carolinus) is a forested wetland specialist wintering in bottomland hardwood forests in the south-eastern U. S. and belongs to the most steeply declining songbirds in the U.S. Little information is available to support priority birds such as the Rusty Blackbird wintering in this threatened habitat. We assessed age and sex distribution and body condition of Rusty Blackbirds among the three major habitats used by this species in the Lower Mississippi Alluvial Valley and also measured food availability. Overall, pecan groves had the highest biomass mainly driven by the amount of nuts. Invertebrate biomass was highest in forests but contributed only a small percentage to overall biomass. Age and sex classes were unevenly distributed among habitats with adult males primarily occupying pecan groves containing the highest nut biomass, females being found in forests which had the lowest nut biomass and young males primarily staying in forest fragments along creeks which had intermediate nut biomass. Males were in better body condition than females and were in slightly better condition in pecan groves. The results suggest that adult males occupy the highest quality habitat and may competitively exclude the other age and sex classes

    Investigating porcine parvoviruses genogroup 2 infection using in situ polymerase chain reaction

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    Abstract Background Porcine parvovirus 2 (PPV2) was detected in swine serum without showing any relationship with disease. The emergence of the virus seemed to be a unique event until other genetically highly similar parvoviruses were identified in China and, later in 2012, the presence of the virus was also described in Europe. PPV2 is widely distributed in pig populations where it is suspected to be involved in respiratory conditions, based on its frequent detection in lung samples. In order to investigate the potential pathogenic involvement of PPV2, 60 dead pigs were examined from two farms. They were necropsied and tested for PPV2 and PCV2 (Porcine circovirus type 2) by PCR; by Brown and Brenn (B&B) staining for bacteria; by immunohistochemistry (IHC) to detect CD3, Swine leukocyte antigen class II DQ (SLAIIDQ), lysozyme, porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza (SIV), Mycoplasma hyopneumoniae (Mhyo); and by in situ hybridization (ISH) to detect ssDNA and dsDNA of PCV2. PPV2 positive samples were subjected to in situ polymerase chain reaction (IS-PCR) including double staining method to detect PPV2 and host cell markers. To calculate statistical difference we used GENMOD or LOGISTIC procedures in Statistical Analysis System (SAS®). Results We found that the PPV2 was localized mostly in lymphocytes in lungs, lymph nodes and liver. Neither CD3 antigen nor lysozyme was expressed by these infected cells. In contrast, low levels of SLAIIDQ were expressed by infected cells, suggesting that PPV2 may have a specific tropism for immature B lymphocytes and/or NK lymphocytes though possibly not T lymphocytes. Conclusion The overall conclusion of this study indicates that PPV2 may contribute to the pathogenesis of pneumonia

    Studying the Properties of Cationic Emulsified Asphalts Paving Mixture at Iraqi Environmental Conditions

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    Emulsified asphalt mixture is generally a mix made of emulsified asphalt with aggregate. Emulsified asphalt is manufactured from base asphalt, emulsifier agent and water. This study aims to study and improve the emulsified asphalt mixtures with using of ordinary Portland cement as filler materials for road construction and maintenance in Iraq as an alternative to the hot asphalt mixtures, due to its economical, practical and environmental advantages. Beside this study focused to test and evaluates the emulsified asphalt material properties to be used as paving mixture. The tested properties of emulsified asphalt mixture were bulk density, air voids, dry Marshall Stability, wet Marshall Stability, retained Marshall Stability, flow tests with different compaction efforts differ from standard Marshall Limitations and compared with the common used specification. The results indicate that the emulsified asphalt type cationic slow setting low viscosity (CSS-1) is very suitable with quartz type of aggregate from Al-Nibaay quarry. From many trial mixes it is found that the best percentages of initial residual bitumen content to produced adequate results for coating test ,mixing ,compaction ,curing and Marshall stability were ranged from (2.5%, 3%,3.5%,4% and 4.5%), and the optimum percentage is (3.5%).Finally it can be conducted that the emulsified asphalt mixture contained Portland cement filler material is a suitable alternative mixture to the hot asphalt mixture for road construction and specially maintenance of roadways in Iraq

    Building International Business Theory: A Grounded Theory Approach

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    The field of international business (IB) is in need of more theory development (Morck & Yeung, 2007). As such, the main focus of our manuscript was to provide guidance on how to build IB specific theory using grounded theory (GT). Moreover, we contribute to future theory development by identifying areas within IB where GT can be applied and the type of research issues that can be addressed using this methodology. Finally, we make a noteworthy contribution by discussing some of GT’s caveats and limitations, particularly those relevant to IB. This effort is intended to spur further interest in the development of IB theory

    Effect of malaria transmission reduction by insecticide-treated bed nets (ITNs) on the genetic diversity of Plasmodium falciparum merozoite surface protein (MSP-1) and circumsporozoite (CSP) in western Kenya

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    Background Although several studies have investigated the impact of reduced malaria transmission due to insecticide-treated bed nets (ITNs) on the patterns of morbidity and mortality, there is limited information on their effect on parasite diversity. Methods Sequencing was used to investigate the effect of ITNs on polymorphisms in two genes encoding leading Plasmodium falciparum vaccine candidate antigens, the 19 kilodalton blood stage merozoite surface protein-1 (MSP-119kDa) and the Th2R and Th3R T-cell epitopes of the pre-erythrocytic stage circumsporozoite protein (CSP) in a large community-based ITN trial site in western Kenya. The number and frequency of haplotypes as well as nucleotide and haplotype diversity were compared among parasites obtained from children <5 years old prior to the introduction of ITNs (1996) and after 5 years of high coverage ITN use (2001). Results A total of 12 MSP-119kDa haplotypes were detected in 1996 and 2001. The Q-KSNG-L and E-KSNG-L haplotypes corresponding to the FVO and FUP strains of P. falciparum were the most prevalent (range 32–37%), with an overall haplotype diversity of > 0.7. No MSP-119kDa 3D7 sequence-types were detected in 1996 and the frequency was less than 4% in 2001. The CSP Th2R and Th3R domains were highly polymorphic with a total of 26 and 14 haplotypes, respectively detected in 1996 and 34 and 13 haplotypes in 2001, with an overall haplotype diversity of > 0.9 and 0.75 respectively. The frequency of the most predominant Th2R and Th3R haplotypes was 14 and 36%, respectively. The frequency of Th2R and Th3R haplotypes corresponding to the 3D7 parasite strain was less than 4% at both time points. There was no significant difference in nucleotide and haplotype diversity in parasite isolates collected at both time points. Conclusion High diversity in these two genes has been maintained overtime despite marked reductions in malaria transmission due to ITNs use. The frequency of 3D7 sequence-types was very low in this area. These findings provide information that could be useful in the design of future malaria vaccines for deployment in endemic areas with high ITN coverage and in interpretation of efficacy data for malaria vaccines based on 3D7 parasite strains

    Study of hadronic event-shape variables in multijet final states in pp collisions at √s=7 TeV

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