Search

A combination of characters, not individually unique, possessed by the corystid, Corystes cassivelaunus, and the two cancrids, Platepistoma nanum and Cancer pagurus, defines a corystoid-type of spermatozoon: the basally bulbous, anteriorly narrowing perforatorium, the extent of this almost to the plasma membrane through a widely perforate operculum, and the simple inner acrosome zone, lacking an acrosome ray zone. The sperm of the two cancrids are closely similar, that of the corystid differing, for instance, in the less pointed, and less tapered, form of the perforatorium. This relative uniformity of spermatozoal ultrastructure in the cancrid+corystid assemblage so far investigated supports inclusion of the two families in the superfamily Corystoidea by Guinot (1978). The combination of perforation of the operculum and absence of an acrosome ray zone (at least in a clearly recognizable form) are features of the Potamidae which possibly indicate that the latter family, modified for a freshwater existence, is related to the cancrid+corystid assemblage. Some elongation of the centrioles, apparent at least in Corystes, may be a further link with potamids in which they are greatly elongated. The coenospermial spermatophores of cancridoids are a notable difference from the cleistospermia of potamids; but the latter is probably an apomorphic modification for fertilization biology. [ABSTRACT FROM AUTHOR]

The spermatozoon of Birgus latro (Linnaeus, 1767) is approx 14 µm in length. It is composed of a large multi-layered oblong-ovoid acrosome which is capped by a conical operculum and lies anterior to a small ring of cytoplasm and an amorphous nucleus which is drawn out into a series of arms or extensions. Originating from the cytoplasmic area are three further long microtubular arms. The sperm of B. latro is very similar to the sperm of the only other genus in the Coenobitidae, Coenobita, of which C. clypeatus is a representative species. They share a suite of ultrastructural characters including: a long, cylindrical, capsule-bound acrosome containing an inner acrosome core, a large acrosome ray zone and a thin outer acrosome zone; an apical operculum anterior to a subopercular zone divided into two areas of differing density; an invaginated perforatorial zone with a bipartite granular matrix; microvillus-like extensions of the inner acrosome core projecting into the perforatorial invagination; a ring of cytoplasm, around the base of the acrosome, containing numerous mitochondria, extensive lamellar systems and the bases of three microtubular arms; granular nuclear material forming irregular arms; and at the posterior portion of the cell membrane a combination of nuclear and plasma membranes. Some ultrastructural characters which separate the two genera are: a domed operculum in C. clypeatus as opposed to a conical one in B. latro; in B. latro there is some residual cytoplasm external to the operculum and centrioles are absent from the mature spermatozoon; in C. clypeatus the inner acrosome core does not appear to invest the perforatorium and a series of dense 'rods' are found subjacent and internal to the operculum. Similarities between the two coenobitids are greater than those shared with the pagurid Eupagurus bernhardus. In this latter species, the acrosome is more ovoid than cylindrical and the acrosome zones are less conspicuous; the operculum is absent from the mature sperm (although present during spermiohistogenesis); no subopercular zone is present; the perforatorium contains longitudinally arranged microtubules and extends the full length of the acrosome; and the nuclear material does not form separate nuclear arms. Sperm ultrastructure supports monophyly of the Paguroidea, while distinguishing coenobitids from pagurids within this superfamily. [ABSTRACT FROM AUTHOR]

The use of β-lactam (BL) and β-lactamase inhibitor combination to overcome BL antibiotic resistance has been validated through clinically approved drug products. However, unmet medical needs still exist for the treatment of infections caused by Gram-negative (GN) bacteria expressing metallo-β-lactamases. Previously, we reported our effort to discover pan inhibitors of three main families in this class: IMP, VIM, and NDM. Herein, we describe our work to improve the GN coverage spectrum in combination with imipenem and relebactam. This was achieved through structure- and property-based optimization to tackle the GN cell penetration and efflux challenges. A significant discovery was made that inhibition of both VIM alleles, VIM-1 and VIM-2, is essential for broad GN coverage, especially against VIM-producing P. aeruginosa . In addition, pharmacokinetics and nonclinical safety profiles were investigated for select compounds. Key findings from this drug discovery campaign laid the foundation for further lead optimization toward identification of preclinical candidates.

A new species of eucalliacid ghost shrimp is described from the Gulf of Oman, Iran. Andamancalliax poorei sp. nov. is the first species of the genus described from Iranian subtidal waters and the third species worldwide. Andamancalliax poorei sp. nov. most resembles A. arafura Poore, 2021 from the Arafura Sea but can be differentiated by characters of the minor cheliped, maxilliped 3 and uropodal endopod.

A third species of Michaelcallianassa Sakai, 2002 is described based on two specimens from subtidal waters of the Persian Gulf. Michaelcallianassa persica sp. nov. resembles M. indica Sakai, 2002 from the Andaman Sea, but can be differentiated by possession of six spines on the cutting edge of the large cheliped, a telson with two pairs of lateral movable spines as well as two spines dorsally in the center of the telson and an exopod with a row of spines on the postero-distal margin. The new species compares favorably with congeners M. indica Sakai, 2002 and M. sinica Liu Liu, 2009 in many diagnostic aspects, including body shape, the relative size and shape of pereopods 2-4, maxilliped 3, and the rostrum. Some limited comparison is made to the related genus Balsscallianassa Sakai, 2011.

Callianassa ehsani sp. nov. is described as a new species from the Gulf of Oman, Iran. It differs from all other members of the subfamily Callianassinae in having a well-developed meral hook on the merus and 6 or 7 acute spines on the ischium of the large cheliped and characters of the small cheliped and telson. This new species is most similar to Callianassa thailandica Sakai, 2005 and Callianassa persica, Sakai, 2005. The generic assignment of the new species is provisional, reflecting the unstable state of the taxonomy of this family.

A new species of callianassid ghost shrimp is described from the Persian Gulf, Iran. Cheramus iranicus sp. nov. is the first member of Cheramus described from Iranian subtidal waters and can be differentiated by a large cheliped with a ventroproximal spine on the merus and 7 spines on the ventral margin of the ischium, the endopod of the uropod has 4 movable spines on the distal margin and the posterior margin of the telson is strongly bilobed with a prominent medial tooth and two pairs of lateral movable spines. It is compared to other described Cheramus-like species showing a high degree of morphological similarity.

Objective: To specify the principles, definition and dimensions of the new nutrition science., Purpose: To identify nutrition, with its application in food and nutrition policy, as a science with great width and breadth of vision and scope, in order that it can fully contribute to the preservation, maintenance, development and sustenance of life on Earth., Method: A brief overview shows that current conventional nutrition is defined as a biological science, although its governing and guiding principles are implicit only, and no generally agreed definition is evident. Following are agreements on the principles, definition and dimensions of the new nutrition science, made by the authors as participants at a workshop on this theme held on 5-8 April 2005 at the Schloss Rauischholzhausen, Justus-Liebig University, Giessen, Germany., Result: Nutrition science as here specified will retain its current 'classical' identity as a biological science, within a broader and integrated conceptual framework, and will also be confirmed as a social and environmental science. As such it will be concerned with personal and population health, and with planetary health--the welfare and future of the whole physical and living world of which humans are a part.

Objective: Agriculture designed to make best use of landscape and to be maximally sustainable would also provide food of the highest nutritional and gastronomic standards, and would inevitably employ a great many people. Thus it would solve the world's food problems, and its principal social problem, at a stroke. But agriculture in practice is designed for a quite different purpose--to generate wealth, in the cause of 'economic growth'. The pressing need is not for more science and technology, but to recognise the true cause of the problems and to re-think priorities., Conclusion: We could all be well fed. Indeed, everyone in the world who is ever likely to be born could be fed to the highest standards of gastronomy as well as of nutrition until humanity itself comes to an end. We already have most of the necessary technique--perhaps all that is needed. We could always do with more excellent science but we need not depend, as we are often told from on high, on the next technological fix. The methods that can provide excellent food would also create a beautiful environment, with plenty of scope for other creatures, and agreeable and stable agrarian economies with satisfying jobs for all. In reality, in absolute contrast, we have created a world in which almost a billion are chronically undernourished; another billion are horribly overnourished, so that obesity and diabetes are epidemic, and rising; a billion live on less than two dollars a day; and a billion live in urban slums--a figure set to increase and probably at least to double over the next half century; while other species are disappearing so fast that biologists speak of mass extinction.

The external morphology and internal structure of the male sexual tube of the hermit crab Micropagurus acantholepis, a member of the family Paguridae from Australian waters, is described in detail using histological thick sectioning and scanning and transmission electron microscopy techniques. This is the first in-depth study of a sexual tube in the Paguroidea, a group where a remarkable number of genera (55.9% in the family Paguridae) with species having these intriguing sexual structures are known. In M. acantholepis a sexual tube is present on the left side, whereas only a gonopore is present on the right side. The tube is used for the delivery of spermatophores to the female and consists of a sheath of cuticular origin surrounding an internal, functional extension of the posterior vas deferens. Pedunculate spermatophores were observed within the lumen and partially extruding from the terminal opening of the tube in preserved specimens. The tube protrudes from the left coxa of the fifth pereopod as an elongate 3-mm-long, hollow, coiled structure with a terminal opening. Exteriorly the tube consists of a conspicuous thick chitinous cuticular ridge throughout its length, and a thin chitinous cuticle with sparse, regularly arranged simple setae. Interior to the cuticle, the tube contains loose connective tissue, secretory cells, oblique muscle, circular muscle, and epithelial cells. The latter cells line a central lumen that runs the length of the sexual tube. The morphology, cellular composition, and function of the tube are discussed., (Copyright 2003 Wiley-Liss, Inc.)