Process optimization for ethanol production from photoperiod-sensitive sorghum: Focus on cellulose conversion

Photoperiod-sensitive sorghum, as a competitive biomass for ethanol production, was investigated to develop an integrated process for improving ethanol yield. Response surface methodology was employed to study the relationship between pretreatment variables (including temperature, sulfuric acid concentration, and reaction time) and cellulose recovery, as well as efficiency of enzymatic hydrolysis (EEH) in the solid part. Recovery yield decreased and EEH increased as the pretreatment temperature, acidic concentration, and reaction time increased. A model was successfully developed to predict total glucose yield with a maximum value of 82.2%. Conditions of co-fermentation were also optimized, and the optimal ethanol yield was obtained with constant-temperature simultaneous saccharification and fermentation at 38 °C. Acetate buffer at a concentration of 50 mM was found helpful for increasing efficiency of enzymatic hydrolysis, as well as ethanol yield. The maximum ethanol yield was 0.21 g ethanol per dry mass at the conditions of 38 °C, 0.05 g yeast/L, and 50 mM acetate buffer. A complete cellulose balance was provided for the whole process.     

Mitochondria in Mammalian Sperm Physiology and Pathology: A Review

While, for a long time, the role of mitochondria in sperm physiology and pathology has been largely ignored, recent research points out the mitochondria as a major organelle with key roles in sperm function both under physiological and biotechnological conditions. This paper briefly reviews these novel findings regarding the role of mitochondria in sperm, paying special attention to the most practical, readily applicable, aspects of the topic such as their role as a major source of the sublethal damage that sperm experiments after cryopreservation.     

Protein degradation by rumen microbes of heat-treated whole cottonseed

In vitro and in situ rumen digestion trials were conducted to measure the effect of heat treatment on protein degradation by rumen microbes of cottonseed autoclaved and dry-heated (120, 140, 160 and 180 C) for different lengths of time (20, 40, 60, 90 and 120 min). Autoclaving (120 C, 1 kg/cm2 of pressure for 60 min) was effective in reducing ammonia nitrogen concentration in vitro, but dry heat at this temperature was without effect. Dry heating caused a linear decrease of in vitro ammonia concentration as temperature increased from 140 to 180 C and as exposure time increased from 20 to 120 min. The in situ results corroborated the in vitro findings. Crude protein disappearance from dacron bags decreased from 87 to 48% as temperature increased from 140 to 180 C after 20 min of heating.     

Changes in Testicular Interstitial Connective Tissue of Hamsters (Mesocricetus auratus) During Ageing and After Exposure to Short Photoperiod

The testicular interstitium of Syrian hamster (Mesocricetus auratus) was studied during ageing and in testicular regression after exposure to a short photoperiod, in relation to the interstitial cells and their connective tissue. This tissue was assessed histochemically using Masson's trichrome technique and the expression of Heat Shock Protein 47 (HSP‐47) and collagen IV (α5) was assessed in Leydig cells. Finally, an ultrastructural analysis of some cells of the testicular interstitium was made. Leydig cells were positive for HSP‐47 and collagen IV (α5). Ageing did not change the parameters studied while the short photoperiod altered the synthetic activity of Leydig cells. The positivity index of these cells for HSP‐47 was significantly higher in the regressed testis, but was lower for collagen IV (α5). During ageing no change were observed. Ultrastructural Leydig cells showed a discontinuous basal lamina that did not change during ageing. The basal lamina was not identified in Leydig cells regressed by exposure to a short photoperiod. In conclusion; the intertubular connective tissue suffers little change with age. By contrast, in the testis regressed after exposure to a short photoperiod the studied parameters related to the intertubular connective tissue were altered. These changes are probably related with the low synthetic activity of regressed Leydig cell.     

Prediction of bluetongue vector distribution in Europe and north Africa using satellite imagery

Bluetongue is an infectious, non-contagious arboviral disease thought to infect all known ruminant species. Since 1998, an unprecedented epizootic of the disease has occurred in the Mediterranean region, resulting in the deaths of over 800,000 sheep to date. Bluetongue virus (BTV) is transmitted by biting midges of which one species, Culicoides imicola, is the major vector in the old world. C. imicola was trapped for 2 years at 87 sites across Portugal and models were developed for predicting the presence and abundance of the midge at these sites. Discriminant analysis was used to identify the best models from 40 temporally Fourier-processed 1 km spatial resolution remotely-sensed variables. The best models correctly predicted presence and absence at 83 of the 87 sites, and abundance at 76 sites. The models were then used to predict C. imicola presence and abundance elsewhere across Europe and north Africa. C. imicola was predicted to be present and in high abundance at the majority of areas affected in the recent bluetongue epizootic, including the Balearics, Sardinia, Corsica, Sicily, areas of mainland Italy, large areas of Greece, western Turkey and northern Algeria and Tunisia.     

A genomewide association study in divergently selected lines in rabbits reveals novel genomic regions associated with litter size traits

Uterine capacity (UC), defined as the total number of kits from unilaterally ovariectomized does at birth, has a high genetic correlation with litter size. The aim of our research was to identify genomic regions associated with litter size traits through a genomewide association study using rabbits from a divergent selection experiment for UC. A high-density SNP array (200K) was used to genotype 181 does from a control population, high and low UC lines. Traits included total number born (TNB), number born alive (NBA), number born dead, ovulation rate (OR), implanted embryos (IE) and embryo, foetal and prenatal survivals at second parity. We implemented the Bayes B method and the associations were tested by Bayes factors and the percentage of genomic variance (GV) explained by windows. Different genomic regions associated with TNB, NBA, IE and OR were found. These regions explained 7.36%, 1.27%, 15.87% and 3.95% of GV, respectively. Two consecutive windows on chromosome 17 were associated with TNB, NBA and IE. This genomic region accounted for 6.32% of GV of TNB. In this region, we found the BMP4, PTDGR, PTGER2, STYX and CDKN3 candidate genes which presented functional annotations linked to some reproductive processes. Our findings suggest that a genomic region on chromosome 17 has an important effect on litter size traits. However, further analyses are needed to validate this region in other maternal rabbit lines.     

Single-Layer Centrifugation Through Colloid Positively Modifies the Sperm Subpopulation Structure of Frozen–Thawed Stallion Spermatozoa

The present study attempted to select the subpopulation of stallion spermatozoa that best survived a conventional freezing and thawing procedure, using centrifugation of post-thawed semen samples through a single layer of a glycidoxypropyltrimethoxysilane-coated silica colloid with a species-specific formulation (Androcoll-E™). After freezing and thawing, four sperm subpopulations were identified, listed as FT1 to FT4. While subpopulations FT1 and FT2 were characterized by low sperm velocity, high velocities characterized the ones called FT3 and FT4. The single-layer centrifugation (SLC)-handled sperm sample was enriched in subpopulation FT3, reaching a proportion of 82.6% of the present spermatozoa, in contrast with the non-filtered control post-thawed semen, where this sperm subpopulation only accounted for 16.3% of the total. It is concluded that in the equine industry, the SLC is a practical, easy-to-perform approach to improve the quality of equine frozen–thawed semen samples.     

Farmers' knowledge,attitudes and practices of rice crop and pest management at Ifugao Rice Terraces,Philippines

A survey of 150 rice farmers in three municipalities of the Ifugao Rice Terraces, Philippines, carried out in June 1998, aimed to assess the farmers' knowledge, attitudes, and practices of rice crop and pest management. The survey revealed that: 54% of the farmers fall within a narrow age range (31-50 years), the majority having 11-30 years of rice farming experience; they are of average literacy; and they have large households. Non-farm activity such as woodcarving was the most common source of additional income. The majority of farmers planted a single crop of rice per year and followed traditional cultivation practices. Major rice crop production constraints were drought due to the El Nino phenomenon and insufficient irrigation infrastructure. Zinc deficiency was widespread. Major, non-insect pests known to farmers were earthworms, rats, golden apple snails, and house sparrows. These pests damage either the rice plant or the terrace wall. Earthworm damage to the terrace wall is most obvious. Farmers had very little exposure to integrated pest management and new rice technologies.     

A Muscodor strain isolated from Citrus sinensis and its production of volatile organic compounds inhibiting Phyllosticta citricarpa growth

Journal of Plant Diseases and Protection - The citrus industry is among the most important worldwide, but citrus plants are affected by a large number of diseases, such as Citrus Black Spot (CBS),...     

A New Source of Resistance to Pseudocercosporella herpotrichoides, Cause of Eyespot Disease of Wheat, Located on Chromosome 4V of Dasypyrum villosum

Resistance to Pseudocercosporella herpotrichoides in five wheat cultivars, accession W6 7283 of Dasypyrum villosum, and ‘Chinese Spring’ disomic addition lines of the D. villosum chromosomes IV, 2V, 4V, 5V, 6V and 7V, was evaluated in seedlings by measuring disease progress 6 weeks after inoculation with a β—glucuronidase—transformed strain of the pathogen and by visual estimates of disease severity. D. villosum and the disomic addition line of chromosome 4V were as resistant as wheat cultivars ‘VPM—1’ and ‘Cappelle Desprez’, but less resistant than ‘Rendezvous’. Resistance of the chromosome 4V disomic addition line was equivalent to that of D. villosum.‘Chinese Spring’ and disomic addition lines of IV, 2V, 5V, 6V and 7V were all susceptible. These results confirm Sparaguee's (1936) report of resistance in D. villosum to P. herpotrichoides and establish the chromosomal location for the genes controlling resistance. The presence of chromosome 4V in the addition line and its homocology to chromosome 4 in wheat were confirmed by Southern analysis of genomic DNA using chromosome group 4-specific clones. This genetic locus is not homoeologous with other known genes for resistance to P. herpotrichoides located on chromosome group 7, and thus represents a new source of resistance to this pathogen.