Developmental pattern of the bony tentorium of spider monkeys (Ateles)

Based on their developmental patterns, the bony tentorium (BT) and bony falx (BF) of mammals can be classified into two types, the carnivoran type and the dolphin type. The former develops as part of the skull bones during the fetal period and is already completed at birth, while the latter is gradually formed by ossification in the tentorium cerebelli (TC) and falx cerebri (FC) during the course of aging. The BT of spider monkeys is assigned to the dolphin type.     

Interfacial water and its potential role in the function of sericin against biofouling

Abstract

Silk sericin is a globular protein whose resistance against fouling is important for applications in biomaterials and water-purification membranes. Here it is shown how sericin generates a water-exclusion zone that may facilitate antifouling behavior. Negatively charged microspheres were used to mimic the surface charge and hydrophobic domains in bacteria. Immersed in water, regenerated silk sericin formed a 100-µm-sized exclusion zone (for micron-size foulants), along with a proton gradient with a decrease of >2?pH-units. Thus, when in contact with sericin, water molecules near the surface restructure to form a physical exclusionary barrier that might prevent biofouling. The decreased pH turns the aqueous medium unviable for neutrophilic bacteria. Therefore, resistance to biofouling seems explainable, among other factors, on the basis of water-exclusionary phenomena. Furthermore, sericin may play a role in triggering the fibroin assembly process by lowering the pH to the required value.     

The optimization of a scaffold for cartilage regeneration

Natural polymers offer various advantages in cartilage tissue engineering applications, thanks to their intrinsic bioactivity and adaptability, which can be exploited for the optimization of scaffold properties. In particular, silk fibroin has multifunctional features driven by the self-assembly of molecular subunits in appropriate environmental conditions. For these reasons, it was used in combination with hyaluronic acid to produce porous sponges for cartilage regeneration. The added amount of hyaluronic acid and the cross-linking with genipin modulated scaffold properties in a synergistic way, showing a strong inter-correlation among macroscopic and microscopic characteristics. Interestingly, hyaluronic acid affected silk fibroin conformation and induced a physical separation between the two material components in absence of genipin. Instead, this was prevented by the cross-linking reaction, resulting in a more interspersed network of protein and polysaccharide molecules partially resembling the structure of cartilage extracellular matrix. In addition, the systematic evaluation of sponge properties and how they can be modulated will represent a significant starting point for the interpretation of the complex outcomes driven by the scaffold in vitro and in vivo.     

Microstructure of the silk apparatus in the coelotine spider Paracoelotes spinivulva (Araneae: Amaurobiidae)

The microstructural characteristics of the silk‐spinning apparatus and its ecological significance in the coelotine spider Paracoelotes spinivulva were examined by field emission scanning electron microscopy, with the goal of understanding the properties and the evolutionary origins of these silk constructs. The silk apparatuses of this spider were composed of four basic types of silk‐spinning spigot (ampullate, pyriform, aciniform and tubuliform), which connected with typical silk glands in the abdominal cavity. Of the three pairs of spinnerets, the posterior pairs were highly elongated along the body axis. Anterior spinnerets comprised two pairs of ampullate glands and approximately 70–80 pairs of pyriform glands in both sexes. Middle spinnerets had one to two pairs of ampullate spigots, three pairs of tubuliform spigots in females, and 50–60 (female) or 80–90 (male) pairs of aciniform spigots. An additional two pairs of tubuliform spigots in females and 70–80 (female) or 100–120 (male) pairs of aciniform spigots were counted on the spinning surfaces of the posterior spinnerets in both sexes. Although the coelotine spiders use their silk to catch prey, P. spinivulva characteristically do not have a typical “triad” spigot, including a flagelliform and two aggregate spigots, for capture thread production.     

Interactive effects of selected pesticides on the two-spotted spider mite and its fungal pathogen Neozygites floridana

Benomyl affected populations of Tetranychus urticae by interfering with the pathogenic fungus, Neozygites floridana. Benomyl delayed but prolonged spider mite outbreaks. Few mites were infected with the pathogen when benomyl was used. Reductions in mite populations treated with fentin hydroxide were associated with a high incidence of N. floridana infection. Benomyl did not affect sporulation of N. floridana but appeared to inhibit conidial germination or growth of the fungus.

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Résumé Le bénomyl a modifié les populations de Tetranychus urticae Koch en interférant avec son champignon pathogène, Neozygites floridana (Weiser & Muma). Le bénomyl retardait mais prolongeait les pullulations de l'acarien. Peu d'acariens étaient infectés par le champignon quand on utilisait du bénomyl. Les réductions des populations d'acariens traitées avec l'hydroxyde de fentine étaient associées à un haut niveau d'infection par N. floridana. Le bénomyl ne modifiait pas la sporulation de N. floridana mais semblait inhiber la germination des conidies ou la croissance du champignon.

     

莴笋地蜘蛛优势种的空间生态位研究

通过对莴笋地蜘蛛优势种的空间生态位研究,发现蜘蛛优势种在每天的上午、中午和下午的空间生态宽度指数值和生态位重叠指数值大小均有较大变化,下午的蜘蛛生态位宽度指数值和生态位重叠指数值较大,上午的次之,中午的最小。