Detailed Analysis of Proton Decay Rate in the Minimal Supersymmetric SO(10) Model

We consider the minimal supersymmetric SO(10) model, where only one {\bf 10} and one $\bar{\bf 126}$ Higgs multiplets have Yukawa couplings with matter multiplets. This model has the high predictive power for the Yukawa coupling matrices consistent with the experimental data of the charged fermion mass matrices, and all the Yukawa coupling matrices are completely determined once a few parameters in the model are fixed. This feature is essential for definite predictions to the proton decay rate through the dimension five operators. We analyze the proton decay rate for the dominant decay modes $p \to K^{+} \bar{\nu}$ by including as many free parameters as possible and varying them. There are two free parameters in the Yukawa sector, while five in the Higgsino sector. It is found that an allowed region exists when the free parameters in the Higgs sector are tuned so as to cancel the proton decay amplitude. The resultant proton lifetime is proportional to $1/\tan^2 \beta$ and the allowed region eventually disappears as $\tan \beta$ becomes large.Comment: 15 pages, 3 figures; the version to appear in JHE

A novel locus for Meckel-Gruber syndrome, MKS3, maps to chromosome 8q24

Meckel-Gruber syndrome (MKS), the most common monogenic cause of neural tube defects, is an autosomal recessive disorder characterised by a combination of renal cysts and variably associated features, including developmental anomalies of the central nervous system (typically encephalcoele), hepatic ductal dysplasia and cysts, and polydactyly. Locus heterogeneity has been demonstrated by the mapping of the MKS1 locus to 17q21-24 in Finnish kindreds, and of MKS2 to 11q13 in North African-Middle Eastern cohorts. In the present study, we have investigated the genetic basis of MKS in eight consanguineous kindreds, originating from the Indian sub-continent, that do not show linkage to either MKS1 or MKS2. We report the localisation of a third MKS locus (MKS3) to chromosome 8q24 in this cohort by a genome-wide linkage search using autozygosity mapping. We identified a 26-cM region of autozygosity between D8S586 and D8S1108 with a maximum cumulative two-point LOD score at D8S1179 (Z(max)=3.04 at theta=0.06). A heterogeneity test provided evidence of one unlinked family. Exclusion of this family from multipoint analysis maximised the cumulative multipoint LOD score at locus D8S1128 (Z(max)=5.65). Furthermore, a heterozygous SNP in DDEF1, a putative candidate gene, suggested that MKS3 mapped within a 15-cM interval. Comparison of the clinical features of MKS3-linked cases with reports of MKS1- and MKS2-linked kindreds suggests that polydactyly (and possibly encephalocele) appear less common in MKS3-linked families

The widespread use of topical antimicrobials enriches for resistance in Staphylococcus aureus isolated from patients with atopic dermatitis.

BACKGROUND: Carriage rates of Staphylococcus aureus on affected skin in atopic dermatitis (AD) are approximately 70%. Increasing disease severity during flares and overall disease severity correlate with increased burden of S. aureus. Treatment in AD therefore often targets S. aureus with topical and systemic antimicrobials. OBJECTIVES: To determine whether antimicrobial sensitivities and genetic determinants of resistance differed in S. aureus isolates from the skin of children with AD and healthy child nasal carriers. METHODS: In this case-control study, we compared S. aureus isolates from children with AD (n = 50) attending a hospital dermatology department against nasal carriage isolates from children without skin disease (n = 49) attending a hospital emergency department for noninfective conditions. Using whole genome sequencing we generated a phylogenetic framework for the isolates based on variation in the core genome, then compared antimicrobial resistance phenotypes and genotypes between disease groups. RESULTS: Staphylococcus aureus from cases and controls had on average similar numbers of phenotypic resistances per isolate. Case isolates differed in their resistance patterns, with fusidic acid resistance (FusR ) being significantly more frequent in AD (P = 0·009). The genetic basis of FusR also differentiated the populations, with chromosomal mutations in fusA predominating in AD (P = 0·049). Analysis revealed that FusR evolved multiple times and via multiple mechanism in the population. Carriage of plasmid-derived qac genes, which have been associated with reduced susceptibility to antiseptics, was eight times more frequent in AD (P = 0·016). CONCLUSIONS: The results suggest that strong selective pressure drives the emergence and maintenance of specific resistances in AD

A Fetal-Maternal Shift of Blood Oxygen Affinity in an Australian Viviparous Lizard, Sphenomorphus quoyii (Reptilia, Scincidae)

Compared to adults, the oxygen affinity of blood from fetal Sphenomorphus quoyii is very much higher: P50 is approximately 70 Torr in adults and 30 Torr in nearly full term embryos (PC02= 17 Torr, T=34 degrees C). Following birth, oxygen affinity decreases gradually and adult values are approached after about 15 weeks, with the onset of winter retreat. Electrophoresis revealed a multiple hemoglobin system in both adults and embryos, but there were no apparent differences between them

Loss of Sexual Reproduction and Dwarfing in a Small Metazoan

Asexuality has major theoretical advantages over sexual reproduction, yet newly formed asexual lineages rarely endure. The success, or failure, of such lineages is affected by their mechanism of origin, because it determines their initial genetic makeup and variability. Most previously described mechanisms imply that asexual lineages are randomly frozen subsamples of a sexual population.We found that transitions to obligate parthenogenesis (OP) in the rotifer Brachionus calyciflorus, a small freshwater invertebrate which normally reproduces by cyclical parthenogenesis, were controlled by a simple Mendelian inheritance. Pedigree analysis suggested that obligate parthenogens were homozygous for a recessive allele, which caused inability to respond to the chemical signals that normally induce sexual reproduction in this species. Alternative mechanisms, such as ploidy changes, could be ruled out on the basis of flow cytometric measurements and genetic marker analysis. Interestingly, obligate parthenogens were also dwarfs (approximately 50% smaller than cyclical parthenogens), indicating pleiotropy or linkage with genes that strongly affect body size. We found no adverse effects of OP on survival or fecundity.This mechanism of inheritance implies that genes causing OP may evolve within sexual populations and remain undetected in the heterozygous state long before they get frequent enough to actually cause a transition to asexual reproduction. In this process, genetic variation at other loci might become linked to OP genes, leading to non-random associations between asexuality and other phenotypic traits

Regulatory and metabolic rewiring during laboratory evolution of ethanol tolerance in E. coli

We have designed an experimental/computational framework for studying complex phenotypes in bacteria.Our framework relies on whole-genome fitness profiling coupled with a module-level analysis to discover pathways that directly affect fitness.As a proof-of-principle, we studied ethanol tolerance in Escherichia coli and we identified key pathways that contribute to this phenotype.We then validated our findings through genetic manipulations, gene-expression profiling, metabolite-level measurements, and stable-isotope labeling

Impact Monitoring of the National Scale Up of Zinc Treatment for Childhood Diarrhea in Bangladesh: Repeat Ecologic Surveys

Charles Larson and colleagues find that 23 months into a national campaign to scale up zinc treatment for diarrhea in children under age 5 years, only 10% of children with diarrhea in rural areas and 20%–25% in urban/municipal areas were getting the treatment

The Non-SUSY Baryonic Branch: Soft Supersymmetry Breaking of N=1 Gauge Theories

We study a non-supersymmetric deformation of the field theory dual to the baryonic branch of Klebanov-Strassler. Using a combination of analytical (series expansions) and numerical methods we construct non-supersymmetric backgrounds that smoothly interpolate between the desired UV and IR behaviors. We calculate various observables of the field theory and propose a picture of soft breaking by gaugino masses that is consistent with the various calculations on the string side.Comment: 32 pages plus many appendixes. One figur

Extragalactic Radio Continuum Surveys and the Transformation of Radio Astronomy

Next-generation radio surveys are about to transform radio astronomy by discovering and studying tens of millions of previously unknown radio sources. These surveys will provide new insights to understand the evolution of galaxies, measuring the evolution of the cosmic star formation rate, and rivalling traditional techniques in the measurement of fundamental cosmological parameters. By observing a new volume of observational parameter space, they are also likely to discover unexpected new phenomena. This review traces the evolution of extragalactic radio continuum surveys from the earliest days of radio astronomy to the present, and identifies the challenges that must be overcome to achieve this transformational change.Comment: To be published in Nature Astronomy 18 Sept 201