Mayville State University

Reproduction, Fertility and Development is an international journal publishing original research , review and comment in the fields of reproduction and developmental biology in humans, domestic animals and wildlife

Polymer composites reinforced with natural fibers have received widespread attention due to the harmful effects of the petroleum derived synthetic polymer waste. In this study, wheat bran (WB), as a new source of natural fiber, has been investigated in manufacturing bio-based composites. Wheat bran was pretreated with sodium hydroxide (NaOH) and the compositions were analyzed. Pretreatment removed fat, starch, and crude protein significantly and resulted in an increase of cellulose content from 10.9% to 29.6%. Polypropylene (PP) was melt-blended with bran in a screw-extruder with and without using a chemical compatibilizer, and test specimens were produced by an injection molder. Composite specimens tested for characterization of different thermophysical properties. A 16.3 % increase in flexural strength was obtained at fiber loading of 20 % or more, while tensile strength was comparable to neat PP using compatibilizer. Moduli increased and impact strength decreased with fiber addition. The highest tensile and flexural moduli were 2838 and 1702 MPa, respectively for WB/PP composite. The highest impact strength reduction was 66 % with WB/PP composite at 30 % loading rate. Thermal expansion coefficient of the WB/PP biocomposites decreased with a highest reduction of 64 %; meaning that WB, a grain by-product, is very promising as functional fibers for polymer materials. The interactions of WB fiber in bio-based polymer matrix for failure mechanism and composite strength were also studied by manufacturing WB/polylactic acid (PLA) composites using fiber loading optimized for WB/PP composite. Inferior mechanical performance of WB/PLA composites was observed compared to neat PLA. Poor adhesion, debonding, and fiber fracture were the dominating micromechanical deformation processes in WB/PP composites, whereas debonding, cavity, and crack formation due to fiber orientation resulted in poor performance of WB/PLA composites. Prospects of WB-based composites present opportunities for growers having beneficial uses of bran and compensating reduced profit margins.

Invitro embryo production (IVP) is an important tool for genetic improvement in small ruminants. Semen quality is one of the most important aspects to consider for the success of this assisted reproductive technique. With ovine IVP, it is a common practice to use fresh semen for IVF, but this could be a problem because the differences between ejaculates from the same animal are well documented and a source of variation in IVP results. The objective of this research was to compare the effect of fresh and frozen–thawed domestic sheep (Ovis aries) semen on IVF for ovine IVP. The research was carried out in the reproduction laboratory at the Palominos Ranch (Jalisco, México). The IVP was performed with a continuous invitro culture system. Ovaries (n=186) were collected from a slaughterhouse (León, México) and transported to the laboratory within 2h in physiological saline solution (0.9% NaCl) supplemented with penicillin G (100IU mL−1) and streptomycin sulphate (100µg mL−1). For IVP, IVF-Bioscience™ media were used for IVM, IVF, and invitro culture (IVC). For IVM, the cumulus–oocyte complexes (COCs) were selected (only grades 1 and 2) and matured for 24h at 38.5°C in 5% CO2 in air and 100% humidity. Matured oocytes (n=1000) were invitro fertilized using either fresh or frozen–thawed semen (Triladyl™; Minitube) from the same sheep, at a concentration of 2×106 sperm mL−1, for 18h in 38.5°C, 5% CO2 in air, and 100% humidity. The presumptive zygotes were denuded by pipetting and set in IVC until Day 7 at 38.5°C, 5% CO2, 5% O2, and 90% N2 at 100% humidity. The percentages of cleavage, embryos with more than 6 cells, and blastocysts on Day 7 of culture were evaluated, based on the initial number of oocytes entering into IVM. Statistical analyses were carried out with the GLM procedure of SAS software (version 9.3; SAS Institute Inc.) to evaluate the results of fresh versus frozen–thawed (α level=0.05). Rates of cleavage, embryos with more than 6 cells, and blastocysts on Day 7 were similar (P>0.05): fresh 52.3±3.0%, 43.6±2.6%, and 34.3±2.9%, respectively; frozen–thawed: 53.3%±3.0, 41.1±2.6%, and 33.3±2.9%, respectively. In conclusion, under the conditions of this research, the use of fresh and frozen–thawed semen had similar results for ovine IVP.

This chapter discusses ways a writing classroom can establish an ecological composition (ecocomposition) curriculum by offering ecological teaching strategies during the reading, invention, drafting, revision, and editing phases of the writing process. Ecological composition should utilize feminist, Indigenous, and local readings; include kinesthetic movement and outdoor environment when discussing invention with students; consider instructors as travel guides to help students navigate drafting and revision within academic discourse; and understand why editing instruction should not be taught as objective knowledge but as the subjective privileging of particular ways of speaking and writing that are connected to class, gender, race, and geography. Though ecocomposition writing processes are ultimately recursive, discussing particular points during the process helps instructors to strategize ways to guide students toward ecological writing. By implementing an ecocomposition curriculum, students develop an environmental and social consciousness in relation to the places they inhabit.

White-tailed deer (WTD) invitro embryo production is not well documented, due to the seasonality of the wildlife species and available hunting permits. The objective of the present study was to conduct IVM and IVF using WTD oocytes vitrified with trehalose (TH) or sucrose (SC). A total of 121 immature oocytes were obtained from ovaries (n=18) using the slicing technique from hunter-slaughtered deer, not more than 2h after death. The WTD oocytes were vitrified using a solid surface vitrification technique in two different groups: 1) TH (n=60) and 2) SC (n=61). Oocyte warming (OW) was done using four concentrations (OW1 1 M, OW2 0.5 M, OW3 0.25 M, and OW4 0 M) in the oocytes after thawing. Then, a sample was used to evaluate viability for TH (n=5) and SC (n=5) (MTT stain (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), 0.5mgmL−1) and nuclear status (NS) for TH (n=4) and SC (n=5) with 4′,6-diamidino-2-phenylindole (1μgmL−1), defining the stage as germinal vesicle (GV), MI, and unable to evaluate (NE). The remaining oocytes (n=88) were used for IVM for 36h in tissue culture medium-199 supplemented with human menopausal hormone (75 UImL−1) and epidermal growth factor (10ngmL−1). The evaluation of NS was defined (GV, MI considered immature and MII matured). The IVF (n=15) took place in Tyrode's albumin lactate pyruvate media supplemented with heparin (10μgmL−1), penicillamine (0.075mgmL−1), hypotaurine (10M), epinephrine (1μM), and bovine serum albumin fraction V (0.4%), with a final semen concentration of 3×106 spermmL−1. Frozen straws of conventional WTD semen were used; the straws were split into 3 parts, with one fraction thawed and capacitated using “swim-up” technique. After 24h of incubation at 38.5°C with 5% CO2, and humidified air, nuclear evaluation was made as fertilized (F), not fertilized (NF), or NE. A Fisher exact test was used (SAS, 9.0 version for Windows), α=0.05. After warming, for the TH group (n=5), viability was 60% and nuclear status (n=4) was 50% GV, 50% MI, and 0% NE. For the SC group (n=5), viability was 40% and nuclear status (n=5) was 60% GV, 20% MI, and 20% NE. After 36h IVM, NS evaluation in the TH group (n=38) was 66% GV, 24% MI, 0% MII, and 10% NE; for the SC group (n=50), 84% GV, 10% MI, 2% MII, and 4% NE, not a statistically significant difference (P>0.05). For IVF after 24h, the NS evaluation in the TH treatment (n=10) was 0% F, 60% NF, and 40% NE versus the SC treatment (n=5) with 20% F, 40% NF, and 40% NE, not a statistically significant difference (P>0.05). A statistically significant difference (P>0.05) was not found between the TH and SC groups with regard to post-thaw viability, IVM, and IVF. Future research with larger numbers of immature or mature oocytes is suggested for further evaluation of both TH and SC for WTD oocyte vitrification for use with invitro-production techniques as a model for other endangered cervid species.

Graphite nanomaterials offer distinct advantages over micro-scale reinforcing fibers in terms of engineering properties and geometric attributes. Thorough dispersion and effective interfacial interactions through proper functionalization of carbon nanofibers are the prerequisites for their effective use in high performance cementitious matrices. Furthermore, use of nano- and micro-scale reinforcements together provides reinforcing effects at different scales, thus rendering balanced gains in engineering properties of the matrix. However, their use in coarser high-performance matrices has not been evaluated thoroughly. The results show improvements in all flexural attributes, impact and abrasion resistance of DSP concrete with addition of 0.16 vol.% of oxidized and poly-acrylic acid physisorbed carbon nanofibers, over the corresponding properties of plain matrix. The results also point to synergetic effect of hybrid reinforcements in improving the various engineering properties of DSP concrete matrix, especially with low modulus polypropylene microfibers.