Hierarchical genetic organization of human cortical surface area

Surface area of the cerebral cortex is a highly heritable trait, yet little is known about genetic influences on regional cortical differentiation in humans. Using a data-driven, fuzzy clustering technique with magnetic resonance imaging data from 406 twins, we parceled cortical surface area into genetic subdivisions, creating a human brain atlas based solely on genetically informative data. Boundaries of the genetic divisions corresponded largely to meaningful structural and functional regions; however, the divisions represented previously undescribed phenotypes different from conventional (non-genetically based) parcellation systems. The genetic organization of cortical area was hierarchical, modular, and predominantly bilaterally symmetric across hemispheres. We also found that the results were consistent with human-specific regions being subdivisions of previously described, genetically based lobar regionalization patterns.     

Kinship categories across languages reflect general communicative principles

Languages vary in their systems of kinship categories, but the scope of possible variation appears to be constrained. Previous accounts of kin classification have often emphasized constraints that are specific to the domain of kinship and are not derived from general principles. Here, we propose an account that is founded on two domain-general principles: Good systems of categories are simple, and they enable informative communication. We show computationally that kin classification systems in the world's languages achieve a near-optimal trade-off between these two competing principles. We also show that our account explains several specific constraints on kin classification proposed previously. Because the principles of simplicity and informativeness are also relevant to other semantic domains, the trade-off between them may provide a domain-general foundation for variation in category systems across languages.     

Case Study of Processing and Insemination Techniques: Attempts to Improve Fertility of an Aged Stallion with Dilute Semen of Poor Quality

The objective of this case study was to investigate whether semen centrifugation and low-dose insemination techniques would improve fertility of an aged subfertile Quarter Horse stallion with low sperm concentration, motility, and morphology in ejaculates. Forty-five mares were bred by one of five treatments (n = 9 per group) using the entire ejaculate as follows: (1) Group Body: body insemination with ejaculate diluted 1:1 in TAMU extender; (2) Group Body-Cent: body insemination after centrifugation and re-suspension of sperm pellet to 1 mL in TAMU extender; (3) Group Horn-Cent: deep horn insemination after centrifugation and re-suspension of sperm pellet to 1 mL in TAMU extender; (4) Group Cent-Hys: hysteroscopic insemination onto the uterotubal papilla after centrifugation and re-suspension of sperm pellet to 200 μL in Kenney-Modified Tyrode’s extender; and (5) Group Dens-Hys: hysteroscopic insemination onto the uterotubal papilla after discontinuous density gradient centrifugation and re-suspension of the sperm pellet in 200-μL Kenney-Modified Tyrode’s extender. Pregnancy rates did not differ among treatment groups (P = .77). Semen centrifugation for low dose insemination did not appear to improve fertility of this subfertile stallion, despite use of entire ejaculates for each individual insemination dose.     

Evaluation of a Campylobacter fetus subspecies venerealis real-time quantitative polymerase chain reaction for direct analysis of bovine preputial samples

The detection and subspeciation of Campylobacter fetus subsp. venerealis (CFV) from veterinary samples is important for both clinical and economic reasons. Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a venereal disease that can lead to serious reproductive problems in cattle, and strict international regulations require animals and animal products to be CFV-free for trade. This study evaluated methods reported in the literature for CFV detection and reports the translation of an extensively tested CFV-specific polymerase chain reaction (PCR) primer set; including the VenSF/VenSR primers and a real-time, quantitative PCR (qPCR) platform using SYBR Green chemistry. Three methods of preputial sample preparation for direct qPCR were evaluated and a heat lysis DNA extraction method was shown to allow for CFV detection at the level of approximately one cell equivalent per reaction (or 1.0 × 10³ CFU/mL) from prepuce. The optimized sample preparation and qPCR protocols were then used to evaluate 3 western Canadian bull cohorts, which included 377 bulls, for CFV. The qPCR assay detected 11 positive bulls for the CFV-specific parA gene target. DNA sequence data confirmed the identity of the amplified product and revealed that positive samples were comprised of 2 sequence types; one identical to previously reported CFV parA gene sequences and one with a 9% sequence divergence. These results add valuable information towards our understanding of an important CFV subspeciation target and offer a significantly improved format for an internationally recognized PCR test.     

Large volcanic aerosol load in the stratosphere linked to Asian monsoon transport

The Nabro stratovolcano in Eritrea, northeastern Africa, erupted on 13 June 2011, injecting approximately 1.3 teragrams of sulfur dioxide (SO(2)) to altitudes of 9 to 14 kilometers in the upper troposphere, which resulted in a large aerosol enhancement in the stratosphere. The SO(2) was lofted into the lower stratosphere by deep convection and the circulation associated with the Asian summer monsoon while gradually converting to sulfate aerosol. This demonstrates that to affect climate, volcanic eruptions need not be strong enough to inject sulfur directly to the stratosphere.     

Toxocara vitulorum in a bison (Bison bison) herd from western Canada

The discovery of the parasite Toxocara vitulorum in bison calves in the province of Manitoba, Canada is discussed. This parasite is more commonly found in the small intestines of bovid calves living in tropical and subtropical regions of the world. This is the first time that Toxocara vitulorum has been reported from hosts in Canada.     

Impact of baiting on feral swine behavior in the presence of culling activities

We studied the effects of baiting on feral swine (Sus scrofa) movements and corresponding likelihood of disease spread under real and simulated culling pressure. Our objectives were to determine the proportion of feral swine that used the bait station site, and if baiting of feral swine altered areas of utilization, distances from location centroids to treatment location (control or bait station), and movement rates by survivors during culling activities. We hypothesized that the bait station would increase the sedentary nature of feral swine, thus reducing the potential for dispersal and hence disease dispersal. Our experiment was conducted between February and May 2011 on the Rob and Bessie Welder Wildlife Foundation (WWF) in San Patricio County, Texas. We trapped 83 feral swine and placed GPS collars on 21 animals. We established and maintained a centralized bait station on one side of the WWF from 13 March to 27 April. We conducted population-wide culling activities, including trapping, controlled shooting, drive shooting, and aerial gunning, from 3 to 27 April and removed 143 feral swine (4.6feral swine/km(2)). Areas of utilization did not differ between treatments (control or bait station). However, we found location centroids of bait station site feral swine to be closer to the treatment location than those of control site animals and daily movement rates of bait station site feral swine to be 39% greater than movement rates of control site animals. Based on our observation that only 62% of feral swine trapped in proximity to the bait station used it, we cannot recommend baiting as an alternative to fences for containing animals during culling activities. However, there is value in using bait stations to describe patterns of feral swine movements, facilitate observation, and improve efficacy when conducting removals.     

Causes and consequences of shifting cultivation and its alternative in the hill tracts of eastern Bangladesh

Shifting cultivation, which is still prevalent in the uplands of eastern Bangladesh, contributes significantly to forest loss and is the main cause of land degradation. This paper presents the causes and consequences of shifting cultivation and its potential land use alternatives. The analysis presented is primarily qualitative with a supplementary quantitative analysis of the causes of forest loss by logistic regression. The results of the study show that traditional land practices, exacerbated by poverty and associated with a lack of technical knowledge is the main cause for the continuation of unsustainable shifting cultivation. Population pressure, inadequate land for cultivation, low education levels, policy planning and implementation without local participation are all factors that influence farmers’ decision to continue shifting cultivation. Intensive land management through agroforestry is a promising alternative that can sustainably manage the remaining forest resources. If adopted, such systems potentially provide good economic returns, and may significantly reduce rural poverty.     

Evaluation of heat-labile enterotoxins type IIa and type IIb in the pathogenicity of enterotoxigenic Escherichia coli for neonatal pigs

Type II heat-labile enterotoxins (LT-II) have been reported in Escherichia coli isolates from humans, animals, food and water samples. The goal here was to determine the specific roles of the antigenically distinguishable LT-IIa and LT-IIb subtypes in pathogenesis and virulence of enterotoxigenic E. coli (ETEC) which has not been previously reported. The prevalence of genes encoding for LT-II was determined by colony blot hybridization in a collection of 1648 E. coli isolates from calves and pigs with diarrhea or other diseases and from healthy animals. Only five isolates hybridized with the LT-II probe and none of these isolates contained genes for other enterotoxins or adhesins associated with porcine or bovine ETEC. Ligated intestinal loops in calves, pigs, and rabbits were used to determine the potential of purified LT-IIa and LT-IIb to cause intestinal secretion. LT-IIa and LT-IIb caused significant secretion in the intestinal loops in calves but not in the intestinal loops of rabbits or pigs. In contrast, neonatal pigs inoculated with isogenic adherent E. coli containing the cloned genes for LT-I, LT-IIa or LT-IIb developed severe watery diarrhea with weight loss that was significantly greater than pigs inoculated with the adherent, non-toxigenic parental or vector only control strains. The results demonstrate that the incidence of LT-II appeared to be very low in porcine and bovine E. coli. However, a potential role for these enterotoxins in E. coli-mediated diarrhea in animals was confirmed because purified LT-IIa and LT-IIb caused fluid secretion in bovine intestinal loops and adherent isogenic strains containing cloned genes encoding for LT-IIa or LT-IIb caused severe diarrhea in neonatal pigs.     

Demonstration of neuraminidase activity in Mycoplasma neurolyticum and of neuraminidase proteins in three canine Mycoplasma species

Neuraminidases are virulence factors in many pathogenic microorganisms. They are present also in some Mycoplasma species that cause disease in birds, dogs and alligators. Thirty-seven Mycoplasma species have been examined previously for neuraminidase (sialidase) activity, whereas many of the species causing disease in man, ruminants, pigs, rodents and other animals have not. In this study neuraminidase enzymatic activity (NEAC) was examined in 45 previously untested Mycoplasma species, including those causing diseases in man, farm animals and laboratory animals. The only species in which NEAC was found was Mycoplasma neurolyticum, specifically, its type strain (Type A(T)) which is capable of inducing neurologic signs in inoculated young mice and rats. The NEAC of washed cells was relatively weak, but it differed even more than 10-fold among cells of cultures derived from individual colonies of M. neurolyticum. A weak NEAC was also detected in the supernatant of the M. neurolyticum broth culture. Canine Mycoplasma spp. with high sialidase activity reported previously, Mycoplasma canis, Mycoplasma cynos and Mycoplasma molare had 100-fold more NEAC than M. neurolyticum, but apparent differences in NEAC levels existed among strains of M. canis and of M. cynos. Zymograms using neuraminidase-specific chromogenic substrate were used to show proteins having NEAC. In M. canis (a field isolate Larissa and the type strain PG14(T)), M. cynos (isolate 896) and M. molare (type strain H542(T)) proteins with NEAC had molecular masses of ～130kDa, 105kDa and 110kDa, respectively. Identification of these neuraminidases could provide the basis for their molecular characterization.