Methyl‐β‐Cyclodextrin Improves Sperm Capacitation Status Assessed by Flow Cytometry Analysis and Zona Pellucida‐Binding Ability of Frozen/Thawed Bovine Spermatozoa

Mammalian sperm undergo a series of biochemical transformations in the female reproductive tract that are collectively known as capacitation. Cyclodextrins added to the sperm culture medium have been described to induce in vitro sperm capacitation, enabling its use in protein‐free media. However, the additive capacitating effect of methyl‐β‐cyclodextrin (MβCD) in the medium containing bovine serum albumin (BSA) is unknown in the bovine species. In this study, we evaluated the effects of incubating frozen–thawed bovine spermatozoa in a BSA‐containing medium supplemented with MβCD on different sperm quality and functional parameters. Sperm viability decreased with the addition of MβCD in a dose‐dependent manner (p < 0.05), and DNA damage could be observed but only with the highest concentration of MβCD. However, pre‐incubation of spermatozoa in MβCD‐supplemented medium improved the capacitation status as assessed by the increase in plasma membrane fluidity, intracellular calcium concentration, induced acrosome reactivity and zona pellucida (ZP)‐binding ability (p < 0.05). Thus, we conclude that MβCD supplementation is able to enhance the capacitation status of frozen–thawed bovine spermatozoa cultured in capacitation medium containing BSA and could result in a valid strategy for its application on artificial reproductive technologies such as in vitro fertilization or intracytoplasmic sperm injection.     

FTIR and Raman Signatures of Wheat Grain Peripheral Tissues

Hand‐dissection of mature grains from three common wheat cultivars (Triticum aestivum L.: Caphorn, Crousty, and Recital) and one durum wheat (T. durum Desf., Ardente) was performed to obtain pure samples of aleurone layer, hyaline layer, outer pericarp, and a composite layer made up of testa+inner pericarp. Vibrational spectral signatures were collected on both sides of the layers by ATR‐FTIR and Raman spectroscopy. Spectra were compared with biochemical analysis on the same samples which allowed identification of specific composition patterns in each tissue regardless of the cultivar. Considering the low penetration depth of ATR‐FTIR signal, the cuticles were evidenced on the external sides of outer pericarp, hyaline layer, and testa. Spectra from testa of red and white wheats were clearly distinguished. FTIR spectroscopy, combined with statistical analysis, was successful in identifying the specific spectral signature for each peripheral tissue of wheat grains. In the 1500–800 cm^‐1 spectral region, multivariate models allowed accurate prediction of the histological origin of the pericarp, hyaline, and aleurone layers regardless of the analyzed side, and the testa but with a lower performance.     

The protein composition of sheep foetal fluids

Amniotic fluid contains several proteins including alpha-foetoprotein derived from the foetal plasma, but lacks the higher molecular weight alpha2- and gamma-globulins. The protein composition of the fluid, like that of the serum, remains unchanged after the first month of gestation, and is buffered from the influence of the allantoic fluid by the amnion. Allantoic fluid contains a significantly higher concentration and a greater variety of proteins; it is not a simple transudate of either foetal or maternal plasma, and though containing proteins derived from both sources, it is deficient in albumin but relatively abundant in gamma-globulins. The latter comprises gamma-foetoprotein and mature type IgG. It is believed that maternal IgG may reach the allantoic sac in appreciable amount, but its transmission to the amniotic sac and thence to the foetus may be prevented by the impermeability of the amnion.     

Monitoring the effects of gypsy moth defoliation on forest stand dynamics on Cape Cod,Massachusetts: Sampling intervals and appropriate interpretations

Gypsy moth (Lymantria dispar L.) outbreaks affect stand dynamics and successional patterns in pine–oak woodlands of North America's Atlantic coastal plain. Species-poor overstories are dominated by pitch pine (Pinus rigida), black oak (Quercus velutina) and white oak (Quercus alba). Both oaks are preferred food for gypsy moth, and white oak is the dominant late-successional species. We documented, over a 21-year period, the effects of gypsy moth defoliation on forest stand dynamics at Cape Cod National Seashore, Massachusetts. Our goal was to better understand the influence of gypsy moth defoliation on temporal changes in stand composition. Tree species abundance and frequency were measured in 16 stands with varying abundances of pitch pine and oak. Regression of 2-dimesional rates of change calculated from principal components analysis showed that gypsy moth significantly influenced stand dynamics and successional patterns between 1981 and 1992/1993. Defoliation was virtually absent in the 1990s, and analysis of 1992/1993–2002 rates of change showed topographic slope to be the most important factor influencing stand dynamics during this time. For the period 1981–2002 rates of change analysis failed to identify either factor as influencing changes in stand dynamics. We conclude that the 1980s defoliation events had a transitory effect on upland forest composition, but that there exists the potential for significant long-term impact due to recurrent defoliation episodes. Stand composition should be monitored at intervals which roughly correspond to the time it takes for stands to recover to disturbance events, in the case of those we sampled, approximately 10 years.     

In‐Depth Study of Durum Wheat Grain Tissue Distribution at Milling

The starchy endosperm proportion in durum wheat grain and its ability to be isolated from the peripheral tissues appear as main intrinsic characteristics potentially related to the milling value but still difficult to assess. In this study, several durum wheat samples displaying distinct grading characteristics were analyzed and processed through a pilot mill. The histological composition of grains and milling fractions was monitored by using identified biochemical markers of each wheat grain tissue. Contrasted milling yields of semolina and flour were observed between samples, despite displaying a similar starchy endosperm proportion determined by hand dissection. These yields were related both to differences in the starchy endosperm extraction and to the presence of the aleurone layer, particularly its cellular content. Furthermore, two distinct types of fractionation behavior of the aleurone layer were distinguished depending on the wheat grain sample. Extraction of the envelopes and embryonic axis into semolina and flours were found negligible in comparison with the other tissues.     

Prediction of relative tissue proportions in wheat mill streams by fourier transform mid-infrared spectroscopy

Fourier-transform mid-infrared (FTIR) spectroscopy was investigated as a method to quantify the relative wheat grain tissue proportion in milling fractions. Spectra were acquired with a FTIR spectrometer equipped with an attenuated total reflectance device on ground samples, and the relative tissue proportion was determined according to the biochemical marker methodology as the reference method. Partial least-squares models were developed independently to predict the amount of outer pericarp, aleurone layer, starchy endosperm, and an intermediate layer (made up of inner pericarp plus seed coat plus nucellar epidermis). Good quality of prediction was obtained regardless of the target tissue. The standard errors of prediction obtained for the outer pericarp, intermediate layer, aleurone layer, and starchy endosperm quantification were, respectively, 3.4, 1.3, 3.4, and 4.6%.     

生态型农业观光园规划设计

通过阐述园区规划设计原则及理论根据,结合实例分析了生态型农业观光园的设计内容,有利于更好的研究与开发农业观光园项目。