פרסומים

In the mid-1960s egg production, fertility, and hatchability of broiler breeder females dropped precipitously. Due to disrupted follicle hierarchies and development of the erratic oviposition and defective eggs (EODES) syndrome. EODES was controlled by restricting feed. In the 1990s, another set of problems arose at entry of broiler breeders into lay and characterized by high mortality followed by lower peak lay and reduction in egg and chick production. These problems are induced by even slight over-feeding, and hence we termed it the “Over Feeding Complex” (OFC). We have speculated that OFC is a quasi-EODES condition, induced by the intense selection for increased breast proportion. To test this, we compared, under fast (FF) and slow (SF) release from feed restriction, body composition and reproductive performance of a broiler breeder from year 1980 (B1980) and kept without selection for performance traits since then, to a line hatched in 2000 (B2000). During the first 16 d of lay, feeding treatment had little effect on egg mass or Laying % for the B1980 birds, while for the B2000 birds, SF treatment resulted in significantly greater egg mass and Laying % compared to FF, showing that the OFC indeed manifested in this experiment. However, contrary to hypothesis, follicle hierarchies were normal for both lines under both feeding treatments. To gain further insight into the OFC syndrome, we here report levels of estradiol, testosterone, and progesterone for these line and treatment groups in the time period leading up to and into lay. A significant line × feeding treatment interaction effect was found for estradiol and testosterone, to a lesser extent for progesterone. For all 3 hormones, for B1980 levels 2 to 3 wk post entry into lay were similar and intermediate under FF and SF, but differed significantly for B2000, being much greater under SF than under FF. Thus, the hormonal effects were parallel and may explain the egg mass and Laying % effects of FF and SF in the 2 genetic types.

Background:The Mediterranean fruit fly Ceratitis capitata is a major pest in horticulture. The development of fly larvae is mediated by bacterial decay in the fruit tissue. Despite the importance of bacteria on larval development, very little is known about the interaction between bacteria and larvae in their true ecological context. Understanding their relationship and inter-dependence in the host fruit is important for the development of new pest control interfaces to deal with this pest.Results:We find no negative effects on egg hatch or larval development brought about by the bacterial isolates tested. The various symbionts inhabiting the fly’s digestive system differ in their degree of contribution to the development of fly larvae depending on the given host and their sensitivity to induced inhibition caused by female produced antimicrobial peptides. These differences were observed not only at the genus or species level but also between isolates of the same species. We demonstrate how the microbiota from the mother’s gut supports the development of larvae in the fruit host and show that larvae play a major role in spreading the bacterial contagion in the infected fruit itself. In addition, we present (for the first time) evidence for horizontal transfer of bacteria between larvae of different maternal origin that develop together in the same fruit.Conclusions:Larvae play a major role in the spread and shaping of the microbial population in the fruit. The transfer of bacteria between different individuals developing in the same fruit suggests that the infested fruit serves as a microbial hub for the amplification and spread of bacterial strains between individuals.

Perovskite solar cells have emerged as a new semi-transparent PV technology for urban infrastructures that demands an explicit trade-off between power conversion efficiency (PCE) and average visible transparency (AVT) which can be adjusted by various modifications in the absorber layer. Here, we introduce a scalable and facile ``one and a half'' step deposition route for mixed cation perovskites patterned in a sub-micron sized grid structure for semi-transparent solar cells. The initial perovskite phase is formed in one step using a grid pattern, while the additional step involves dipping of the pre-deposited perovskite grid in a hot solution of formamidinium iodide (FAI) in isopropanol (IPA). Detailed analysis suggests that the additional step increases pore filling, crystal quality, and grain size and lowers the content of residual PbI2 as well as reveals improved photo physical properties. An average PCE ∼10% with an AVT of 28% is attained with a gold contact for the champion semi-transparent solar cell. The proposed deposition route can be generalized for all other types of perovskite based devices to yield better efficiency.

Demand for household insurance is intuitively perceived as contributing to household and community resilience. However the causality in this relationship is not clear. This paper examines household insurance expenditure and the generation of urban resilience as jointly determined. Potential endogeneity is purged by estimating this relationship as a system and using an instrumental variable approach. Empirical analysis based on aggregated Israeli household expenditure data is used. Results show that instrumenting makes a difference, that a distinction needs to be drawn between personal resilience and environmental resilience and that insurance coverage has an independent effect on resilience different to that of classic social (personal) and economic (property and place-based) characteristics. The policy context of the findings are discussed.

Demand for household insurance is intuitively perceived as contributing to household and community resilience. However the causality in this relationship is not clear. This paper examines household insurance expenditure and the generation of urban resilience as jointly determined. Potential endogeneity is purged by estimating this relationship as a system and using an instrumental variable approach. Empirical analysis based on aggregated Israeli household expenditure data is used. Results show that instrumenting makes a difference, that a distinction needs to be drawn between personal resilience and environmental resilience and that insurance coverage has an independent effect on resilience different to that of classic social (personal) and economic (property and place-based) characteristics. The policy context of the findings are discussed.

Fracture of highly stretched materials challenges our view of how things break. We directly visualize rupture of tough double-network gels at >50% strain. During fracture, crack tip shapes obey a x∼y1.6 power law, in contrast to the parabolic profile observed in low-strain cracks. A new length scale â.," emerges from the power law; we show that â.," scales directly with the stored elastic energy and diverges when the crack velocity approaches the shear wave speed. Our results show that double-network gels undergo brittle fracture and provide a testing ground for large-strain fracture mechanics.

In the interaction of microwave radiation and human beings, the skin is traditionally considered as just an absorbing sponge stratum filled with water. In previous works, we showed that this view is flawed when we demonstrated that the coiled portion of the sweat duct in upper skin layer is regarded as a helical antenna in the sub-THz band. Experimentally we showed that the reflectance of the human skin in the sub-THz region depends on the intensity of perspiration, i.e. sweat duct's conductivity, and correlates with levels of human stress (physical, mental and emotional). Later on, we detected circular dichroism in the reflectance from the skin, a signature of the axial mode of a helical antenna. The full ramifications of what these findings represent in the human condition are still unclear. We also revealed correlation of electrocardiography (ECG) parameters to the
sub-THz reflection coefficient of human skin. In a recent work, we developed a unique simulation tool of human skin, taking into account the skin multi-layer structure together with the helical segment of the sweat duct embedded in it. The presence of the sweat duct led to a high specific absorption rate (SAR) of the skin in extremely high frequency band. In this paper, we summarize the physical evidence for this phenomenon and consider its implication for the future exploitation of the electromagnetic spectrum by wireless communication. Starting from July 2016 the US Federal Communications Commission (FCC) has adopted new rules for wireless broadband operations above 24 GHz (5 G). This trend of exploitation is predicted to expand to higher frequencies in the sub-THz region. One must consider the implications of human immersion in the electromagnetic noise, caused by devices working at the very same frequencies as those, to which the sweat duct (as a helical antenna) is most attuned. We are raising a warning flag against the unrestricted use of sub-THz technologies for communication, before the possible consequences for public health are explored.

Detailed anatomical studies of the human skin using optical coherence tomography (OCT) have revealed that the morphological structure of our eccrine sweat ducts is remarkably helical. These findings have raised the hypothesis that human sweat ducts can be the biological equivalent of helical antennas and hence resemble their electromagnetic (EM) behavior by receiving signals in the sub-THz frequency range. Here we show how this hypothesis evolved and was experimentally tested over the recent years, driven by the prospect of developing remote sensors for obtaining information about our physiological and mental state, as well as better understanding the consequences of using this frequency band for communications in the very near future.

Human umbilical cord blood (HUCB) transplantation has become an alternative cell therapy for hematological and oncological malignancies in the clinic and is considered for neurological disorders. The heterogeneity in the content of the different stem and progenitor cells composing HUCB mononuclear cells (MNC) may influence their engraftment and neurotherapeutic effect. We hypothesized that CD45 pan-hematopoietic marker expression is heterogeneous in MNC, and therefore, CD45(+) subpopulation enrichment for neurotherapy may provide a tool to overcome cellular variance in different HUCB units. We employed an immunomagnetic separation method to isolate and characterize HUCB CD45(+) pan-hematopoietic subpopulation and to investigate whether the vaginal or cesarean deliveries influence their neurotherapeutic effect in a traumatic brain injury (TBI) mouse model. Adult C57BL/6J male mice were subjected to moderate TBI and intravenously xenotransplanted with 1 × 10(6) CD45(+) cells derived from either vaginal or cesarean HUCB units. A large heterogeneity in the expression of CD45 marker in MNC, both in vaginal and cesarean HUCB units, was found, regardless of the number of live births. A higher expression of hematopoietic markers was found in the CD45(+) subpopulation while low expressional levels of typical mesenchymal markers were detected. Neurotherapeutic effects, evaluated with an established neurological severity score and novel object recognition test, indicated improved functional motor and memory recovery and found independent of delivery type. Cytokine analysis in extracts of TBI brain cortices indicated an acute immunomodulatory effect by HUCB CD45(+) subpopulation upon xenotransplantation. These results may provide insights to CD45 marker as a predictor of HUCB units' quality for neurotherapy in TBI.

Metal–organic frameworks (MOFs) are a well-developed field of materials, having a high potential for various applications such as gas storage, water purification, and catalysis. Despite the continuous discoveries of new MOFs, so far there are only a limited number of industrial applications, partially due to their low chemical stability and limited mechanical properties, as well as difficulties in integration within functional devices, Herein, a new approach is presented toward the fabrication of MOF-based devices, utilizing direct 3D printing. By this method, 3D, flexible, and hydrolytically stable MOF-embedded polymeric structures are fabricated. It is found that the adsorption capacity of the 3D-printed MOF is retained, with significantly improved hydrolytic stability of the printed MOFs (copper benzene-1,3,5-tricarboxylate) compared to the MOF only. It is expected that applying 3D printing technologies, for the fabrication of functional MOF objects such as filters and matrices for columns and flow reactors, will open the way for utilization of this important class of materials.

Cholesterol is the only lipid whose absorption in the gastrointestinal tract is limited by gate-keeping transporters and efflux mechanisms, preventing its rapid absorption and accumulation in the liver and blood vessels. In this review, I explored the current data regarding cholesterol accumulation in liver cells and key mechanisms in cholesterol-induced fatty liver disease associated with the activation of deleterious hypoxic and nitric oxide signal transduction pathways. Although nonalcoholic fatty liver disease (NAFLD) affects both obese and nonobese individuals, the mechanism of NAFLD progression in lean individuals with healthy metabolism is puzzling. Lean NAFLD individuals exhibit normal metabolic responses, implying that liver damage is not associated with impaired metabolism per se and that direct lipotoxic effects are crucial for disease progression. Several redox and oxidant signaling pathways involving cholesterol are at play in fatty liver disease development. These include impairment of the mitochondrial and lysosomal function by cholesterol loading of the inner-cell membranes; formation of cholesterol crystals and hepatocyte degradation; and crown-like structures surrounding degrading hepatocytes, activating Kupffer cells, and evoking inflammation. The current review focuses on the induction of liver inflammation, fibrosis, and steatosis by free cholesterol via the hypoxia-inducible factor 1 (HIF-1), a main oxygen-sensing transcription factor involved in all stages of NAFLD. Cholesterol loading in hepatocytes can result in chronic HIF-1 activity because of the decreased oxygen availability and excessive production of nitric oxide and mitochondrial reactive oxygen species.