Yet Another Mechanism of HIV Reverse Transcriptase Inhibition?

Abstract

Bicyclonucleosides like 3 are active against HIV-1 and HIV-2 after phosphorylation. They most probably act as their native bicyclic form fundamentally different, structurally, from that of AZT.     

On Sympathetic Innervation of Muscle Spindles of the Frog Rana temporaria

The work is concerned with solution of a questionable problem, whether there exists a direct sympathetic innervation of muscle spindles. On the isolated total preparations of muscle spindles, with the aid of a specific histochemical fluorescent method using glyoxylic acid, revealed is the sympathetic innervation of these structures: adrenergic terminal axons were found both on the intrafusal muscular fibers and the blood vessels supplying the receptor.     

The Fine Structure of a Multiterminal Innervation of an Insect Muscle

The detailed structure of nerve branches, neuromuscular junctions, and muscle fibers of a multiterminal innervation of cockroach abdominal muscle has been studied with the electron microscope. The muscle fiber is of the banded myofibril type; with paired mitochondria and abundant endoplasmic reticulum. The peripheral nerve branches are multiaxonal with large central axon and several small peripheral tunicated axons. Tracheoblasts closely accompany the nerve branches. The multiple neuromuscular junctions show typical axonal vesicles, muscle aposynaptic granules, and close plasma membrane apposition with no interposition of basement membrane material.     

Yet Another Empty Forest: Considering the Conservation Value of a Recently Established Tropical Nature Reserve

The primary approach used to conserve tropical biodiversity is in the establishment of protected areas. However, many tropical nature reserves are performing poorly and interventions in the broader landscape may be essential for conserving biodiversity both within reserves and at large. Between October 2010 and 2012, we conducted bird surveys in and around a recently established nature reserve in Xishuangbanna, China. We constructed a checklist of observed species, previously recorded species, and species inferred to have occurred in the area from their distributions and habitat requirements. In addition, we assessed variation in community composition and habitat specificity at a landscape-scale. Despite the fact that the landscape supports a large area of natural forest habitat (~50,000 ha), we estimate that >40% of the bird fauna has been extirpated and abundant evidence suggests hunting is the primary cause. A large proportion (52%) of the bigger birds (>20 cm) were extirpated and for large birds there was a U-shaped relationship between habitat breadth and extirpation probability. Habitat specificity was low and bird communities were dominated by widespread species of limited conservation concern. We question whether extending tropical protected area networks will deliver desired conservation gains, unless much greater effort is channeled into addressing the hunting problem both within existing protected areas and in the broader landscape.     

A Deluge? Which Deluge?: Yet Another Facet of the Problem of the Copper Hoard Culture

"Copper hoards" found in the Gagā Valley over the past century and a half remain enigmatic. Some attribute them to the invading Aryans, others to the Harappan refugees, and still others to the indigenous people. Be that as it may, circumstantial evidence suggests the association of the hoards with the so-called "Ocher Color Ware," datable to a period prior to c. 1200 b.c. However, at almost all the sites the potsherds occur sporadically, in a deposit of neat earth bereft of any signs of habitation like ash, flooring material, or the like, and with the deposit itself imperceptibly merging into the natural soil. How did the sherds find their way to the places where they are found? Could the deposits have been waterlogged? If so, it would mean that an area of over 60,000 square kilometers had gone under water at some time. Was this waterlogging due to incessant rain over a long period, or to the diversion of the waters of the Ghaggar, a tributary of the Indus, to the Gagāa system, or to the bunding-up of the latter at some stage? The matter is far from clear and requires detailed investigation.     

The Nerve Supply to the Second Metamere Basicranial Muscle in Osteolepiform Vertebrates,with Some Remarks on the Basic Composition of the Endocranium

The endocranium of Devonian osteolepiforms includes four minor structures, called zygals, which probably represent cephalic vertebral elements belonging to the second, third, and fourth metameres. Also, the endocranium exhibits a partial segmentation in the form of vestiges of intrametameric articulations attributable to the anterior five metameres. Finally, the basicranial muscle of osteolepiforms, extending across the lower part of the endocranial articulation within the second metamere, is possibly supplied by a separate cranial nerve, for which the term nervus rarus is proposed. This hypothetical cranial nerve, which in osteolepiforms possibly emerges from the endocranium through a canal in the fourth metamere, is suggested to constitute, together with the trochlear nerve, the somatic motor component of the second cranionerval segment.     

Basicranial anatomy of Plio-Pleistocene hominids from East and South Africa

The results of a metrical analysis of the basicranium of 19 Plio-Pleistocene fossil hominid crania are presented. The sample includes crania attributed to Australopithecus africanus, Australopithecus boisei, and robustus, and Homo erectus as well as crania whose attribution is still under discussion. These results confirm significant differences between the cranial base patterns of the "gracile" and "robust" australopithecines and the three crania attributed to Homo erectus have a pattern which resembles that of modern humans. None of the crania examined from East Africa sites have base patterns which resemble that of the "gracile" australopithecines. The crania KNM-ER 407 and 732 have patterns which are compatible with them being smaller-bodied females of Australopithecus boisei; KNM-ER 1470 and 1813 have base patterns which most closely resemble that of Homo erectus. The cranial base pattern of KNM-ER 1805 is compatible with its inclusion in either Australopithecus boisei or Homo. When account is taken of the immaturity of Taung, the evidence of its cranial base pattern suggests that if it had reached adulthood it would have resembled the "gracile" australopithecine crania from Sterkfontein and Makapansgat.