In vitro penetration of swine oocytes by homologous spermatozoa: Distinct systems for gamete's co-incubation and oocyte's cryopreservation

In vitro penetration (IVP) of swine oocytes by homologous spermatozoa was evaluated in two experiments using four boars as semen donors. In experiment 1, the IVP rate and the number of penetrating spermatozoa (PSP) were compared using three co-incubation systems for vitrified oocytes and fresh sperm: (1) 35 mL petri dishes in a CO₂ incubator, (2) 35 mL petri dishes in bags (submarine system) and (3) glass flasks partially submerged in water bath with the same gas mixture used for the bag system. Mean PSP was 8.2 ± 10.1 and the IVP rate was 90.5%. The PSP differed across all systems (P = 0.0006): 15.5 ± 0.5 for flasks, 6.3 ± 0.4 for CO₂, and 3.9 ± 0.4 for bags. The IVP rate for flasks (95.0%) was greater (P = 0.01) than for CO₂ and bags (90.8% and 85.0%, respectively), but it did not differ between flasks and CO₂ for three boars (P > 0.05). In experiment 2, co-incubation was done as described for glass flasks in experiment 1. The IVP rate and PSP were compared for cryopreserved oocytes: either vitrified in open pulled straws (OPS), or frozen in cryotubes. Mean PSP was 5.4 ± 6.5 and IVP rate was 89.6%. Both PSP and IVP rate were greater (P < 0.0001) for oocytes frozen in cryotubes (7.0 ± 0.3% and 95.8%, respectively) than those frozen in OPS (3.7 ± 0.3% and 83.4%, respectively), with no differences found for three boars (P > 0.05). In summary, successful IVP of swine oocytes by homologous spermatozoa can be achieved using gametes incubated in glass flasks and oocytes frozen in cryotubes.     

Stuttered swallowing: Electric stimulation of the right insula interferes with water swallowing. A case report

Background  

Various functional resonance imaging, magnetoencephalographic and lesion studies suggest the involvement of the insular cortex in the control of swallowing. However, the exact location of insular activation during swallowing and its functional significance remain unclear.     

The Influence of Culture on Agroecosystem Structure: A Comparison of the Spatial Patterns of Homegardens of Different Ethnic Groups in Thailand and Vietnam

Different ethnic groups have evolved distinctive cultural models which guide their interactions with the environment, including their agroecosystems. Although it is probable that variations in the structures of homegardens among separate ethnic groups reflect differences in the cultural models of the farmers, empirical support for this assumption is limited. In this paper the modal horizontal structural patterns of the homegardens of 8 ethnic groups in Northeast Thailand and Vietnam are described. Six of these groups (5 speaking Tai languages and 1 speaking Vietnamese) live in close proximity to each other in separate villages in Northeast Thailand, and 2 of the groups (one Tai-speaking and one Vietnamese-speaking) live in different parts of Vietnam. Detailed information on the horizontal structure of homegardens was collected from samples of households belonging to each group. Although each ethnic group has a somewhat distinctive modal structure, the groups cluster into 2 different types. The Tai speaking Cao Lan, Kalaeng, Lao, Nyaw, and Yoy make up Type I while both of the Vietnamese groups, along with the Tai speaking Phu Thai, belong to Type II. Type I gardens have predominantly organic shapes, indeterminate boundaries, polycentric planting patterns, and multi-species composition within planting areas. Type II homegardens have geometric shapes, sharp boundaries, lineal planting patterns, and mono-species composition of planting areas. That the homegardens of most of the Tai ethnic groups share a relatively similar horizontal structural pattern that is quite different from the pattern shared by both of the Vietnamese groups suggests that the spatial layout of homegardens is strongly influenced by their different cultural models.     

Dynamic Evolution of Oryza Genomes Is Revealed by Comparative Genomic Analysis of a Genus-Wide Vertical Data Set

Oryza (23 species; 10 genome types) contains the world's most important food crop — rice. Although the rice genome serves as an essential tool for biological research, little is known about the evolution of the other Oryza genome types. They contain a historical record of genomic changes that led to diversification of this genus around the world as well as an untapped reservoir of agriculturally important traits. To investigate the evolution of the collective Oryza genome, we sequenced and compared nine orthologous genomic regions encompassing the Adh1-Adh2 genes (from six diploid genome types) with the rice reference sequence. Our analysis revealed the architectural complexities and dynamic evolution of this region that have occurred over the past ~15 million years. Of the 46 intact genes and four pseudogenes in the japonica genome, 38 (76%) fell into eight multigene families. Analysis of the evolutionary history of each family revealed independent and lineage-specific gain and loss of gene family members as frequent causes of synteny disruption. Transposable elements were shown to mediate massive replacement of intergenic space (>95%), gene disruption, and gene/gene fragment movement. Three cases of long-range structural variation (inversions/deletions) spanning several hundred kilobases were identified that contributed significantly to genome diversification.     

New solvent-producing Clostridium sp. strains, hydrolyzing a wide range of polysaccharides, are closely related to Clostridium butyricum

Thirteen new Clostridium strains, previously isolated from soil and found to produce high amounts of solvents from glucose, hydrolyzed a great variety of α- and β-glycans, including raw starch, xylan, pectin, inulin and cellulose. The sequences of the PCR-amplified DNA fragments containing the variable 3′ part of one of the 16S rRNA genes were 99.5% identical. The macrorestriction pattern of two endonucleolytic digests of chromosomal DNA in the pulsed-field gel electrophoresis (PFGE) confirmed their high homogeneity on the DNA level. The complete 16S rRNA gene sequence of three selected strains was 99.8% identical to the 16S rRNA gene sequence from Clostridium butyricum and separates them from C. acetobutylicum. To the closely related four species of solventogenic clostridia a new group of strains has to be added, which has a great potential for the direct fermentation of biomass. Journal of Industrial Microbiology & Biotechnology (2001) 27, 329–335. Received 12 September 2000/ Accepted in revised form 25 July 2001     

A Burning Issue: Rethinking the Transition from Hunter‐Gatherer to Industrial Sociometabolic Regimes

Hunter‐gatherers are commonly seen as having a fundamentally different sociometabolic regime from agrarian and industrial societies because they are thought to directly appropriate the products of natural ecosystems without modifying those systems in order to enhance their productivity. However, ethnographic and archeological evidence reveals that many hunter‐gatherers extensively employed fire to manage their ecosystems so as to increase production of desirable wild resources, thus engaging in “colonization of nature” that is not qualitatively different from that practiced by other types of society. They systematically burned wild vegetation in order to increase populations of edible wild plants consumed by humans and promote growth of forage for game animals. Deliberate ecosystem burning by Australian Aborigines represented an energy expenditure of 1,512 gigajoules per capita per year (GJ/capita/yr), a level of energy use that is more than three times higher than the United States (445 GJ/capita/yr). It is their profligate consumption of biomass energy that explains why the quality of life of many hunter‐gatherers was often better than that of traditional settled peasant farmers. Hence, the extent to which hunter‐gatherers have a distinct type of sociometabiolic regime is called into question. It can be argued that in the course of social evolution, there have been only two sociometabolic regimes. In one type, which includes hunter‐gatherers, swidden agriculturalists, and industrial societies, extrasomatic energy does most of the productive work, whereas in the other type, that of premodern settled agriculturalists, production is largely dependent on human muscle power.     

msmsEval: tandem mass spectral quality assignment for high-throughput proteomics

Background  

In proteomics experiments, database-search programs are the method of choice for protein identification from tandem mass spectra. As amino acid sequence databases grow however, computing resources required for these programs have become prohibitive, particularly in searches for modified proteins. Recently, methods to limit the number of spectra to be searched based on spectral quality have been proposed by different research groups, but rankings of spectral quality have thus far been based on arbitrary cut-off values. In this work, we develop a more readily interpretable spectral quality statistic by providing probability values for the likelihood that spectra will be identifiable.     

Copulation exposes female Red-winged Blackbirds to bacteria in male semen

One often cited but poorly studied cost of multiple mating by female birds is the risk of acquiring sexually transmitted pathogens. We examined the ejaculates of male Red-winged Blackbirds Agelaius phoeniceus to determine if exposure to bacteria from males was a potential consequence of copulation for females. Ejaculates were collected in the field using a model female fitted with a sterile artificial cloaca. We found that 11 of 18 sampled males left ejaculates containing bacteria (compared to 3 of 18 control swabs of a sterile cloaca similarly exposed to the environment). We could identify to species or genus 13 of 26 isolates of bacteria from ejaculates, and found that each male left a unique combination of types. Only three types were found in more than one male (one additional male in each case). We found no qualitative effects of bacterial contamination on male fertility or female reproductive success, but larger sample sizes would be needed for a quantitative analysis. Little information is available on how the strains we identified might affect birds, but several types have known debilitating effects in humans or domesticated mammals. Two bacterial types isolated from blackbird semen are reported to produce chitinase, an enzyme with possibly beneficial consequences if produced by bacteria entering the gut of an insect-eating bird. These results suggest that exposure to new bacterial types is a consequence of extra-pair copulations to females. This exposure could have beneficial and/or detrimental effects on female fitness.     

Loss of alveolar membrane diffusing capacity and pulmonary capillary blood volume in pulmonary arterial hypertension

Background

Reduced gas transfer in patients with pulmonary arterial hypertension (PAH) is traditionally attributed to remodeling and progressive loss of pulmonary arterial vasculature that results in decreased capillary blood volume available for gas exchange.

Methods

We tested this hypothesis by determination of lung diffusing capacity (DL) and its components, the alveolar capillary membrane diffusing capacity (D_m) and lung capillary blood volume (V_c) in 28 individuals with PAH in comparison to 41 healthy individuals, and in 19 PAH patients over time. Using single breath simultaneous measure of diffusion of carbon monoxide (DL_CO) and nitric oxide (DL_NO), DL and D_m were respectively determined, and V_c calculated. D_m and V_c were evaluated over time in relation to standard clinical indicators of disease severity, including brain natriuretic peptide (BNP), 6-minute walk distance (6MWD) and right ventricular systolic pressure (RVSP) by echocardiography.

Results

Both DL_CO and DL_NO were reduced in PAH as compared to controls and the lower DL in PAH was due to loss of both D_m and V_c (all p < 0.01). While DL_CO of PAH patients did not change over time, DL_NO decreased by 24 ml/min/mmHg/year (p = 0.01). Consequently, D_m decreased and V_c tended to increase over time, which led to deterioration of the D_m/V_c ratio, a measure of alveolar-capillary membrane functional efficiency without changes in clinical markers.

Conclusions

The findings indicate that lower than normal gas transfer in PAH is due to loss of both D_m and V_c, but that deterioration of D_m/V_c over time is related to worsening membrane diffusion.