Determination of the effect of the dam age, birth type, and sex on growth curve traits of hair goat kids.

This study was conducted to investigate the best-fit growth curve and dam age, sex, and birth type effect on growth curve traits of hair goat kids. Monthly 3858 test day body weight (BW) records of 643 hair goat kids from birth to 150 days of age were used to determine the best-fit growth curve and estimate growth curve parameters with Gompertz and Von Bertalanffy models. The BW records were assigned to three groups: dam age (3, 4, 5, 6, 7 years), sex (female, male), and birth type (single, twin). The Gompertz model gave more consistent results than the Von Bertalanffy model according to the goodness of fit criteria. Dam age had no significant effect on any of the growth curve traits. Sex of kids showed a significant effect on maturity index (parameter K) (P < 0.001), estimated mature body weight (parameter A), and weight at point of inflection (IPW) (P < 0.01). Also, birth type had a significant effect on initial/birth weight (parameter B) and parameter K (P < 0.001). Age at point of inflection (IPT) was not affected by any of the factors. Twin kids had a higher maturity index than singles while females higher than males. In conclusion, the Gompertz model was the most suitable model for hair goat kids for selection strategies. For proper selection, the effect of sex and birth type on growth curve traits should be considered by hair goat breeders.

Piezoelectric Multi-Channel Bilayer Transducer for Sensing and Filtering Ossicular Vibration.

This paper presents an acoustic transducer for fully implantable cochlear implants (FICIs), which can be implanted on the hearing chain to detect and filter the ambient sound in eight frequency bands between 250 and 6000 Hz. The transducer dimensions are conventional surgery compatible. The structure is formed with 3  × 3 × 0.36 mm active space for each layer and 5.2 mg total active mass excluding packaging. Characterization of the transducer is carried on an artificial membrane whose vibration characteristic is similar to the umbo vibration. On the artificial membrane, piezoelectric transducer generates up to 320.3 mVpp under 100 dB sound pressure level (SPL) excitation and covers the audible acoustic frequency. The measured signal-to-noise-ratio (SNR) of the channels is up to 84.2 dB. Sound quality of the transducer for fully implantable cochlear implant application is graded with an objective qualification method (PESQ) for the first time in the literature to the best of the knowledge, and scored 3.42/4.5.

A pumpless monolayer microfluidic device based on mesenchymal stem cell-conditioned medium promotes neonatal mouse in vitro spermatogenesis.

BACKGROUND: Childhood cancer treatment-induced gonadotoxicity causes permanent infertility/sub-infertility in nearly half of males. The current clinical and experimental approaches are limited to cryopreservation of prepubertal testicular strips and in vitro spermatogenesis which are inadequate to achieve the expanded spermatogonial stem/progenitor cells and spermatogenesis in vitro. Recently, we reported the supportive effect of bone marrow-derived mesenchymal cell co-culture which is inadequate after 14 days of culture in static conditions in prepubertal mouse testis due to lack of microvascular flow and diffusion. Therefore, we generated a novel, pumpless, single polydimethylsiloxane-layered testis-on-chip platform providing a continuous and stabilized microfluidic flow and real-time cellular paracrine contribution of allogeneic bone marrow-derived mesenchymal stem cells. METHODS: We aimed to evaluate the efficacy of this new setup in terms of self-renewal of stem/progenitor cells, spermatogenesis and structural and functional maturation of seminiferous tubules in vitro by measuring the number of undifferentiated and differentiating spermatogonia, spermatocytes, spermatids and tubular growth by histochemical, immunohistochemical, flow cytometric and chromatographic techniques. RESULTS: Bone marrow-derived mesenchymal stem cell-based testis-on-chip platform supported the maintenance of SALL4(+) and PLZF(+) spermatogonial stem/progenitor cells, for 42 days. The new setup improved in vitro spermatogenesis in terms of c-Kit(+) differentiating spermatogonia, VASA(+) total germ cells, the meiotic cells including spermatocytes and spermatids and testicular maturation by increasing testosterone concentration and improved tubular growth for 42 days in comparison with hanging drop and non-mesenchymal stem cell control. CONCLUSIONS: Future fertility preservation for male pediatric cancer survivors depends on the protection/expansion of spermatogonial stem/progenitor cell pool and induction of in vitro spermatogenesis. Our findings demonstrate that a novel bone marrow-derived mesenchymal stem cell-based microfluidic testis-on-chip device supporting the maintenance of stem cells and spermatogenesis in prepubertal mice in vitro. This new, cell therapy-based microfluidic platform may contribute to a safe, precision-based cell and tissue banking protocols for prepubertal fertility restoration in future.