The histomorphological structure of the male reproductive system of maize leaf weevil Tanymecus dilaticollis Gyllenhal, 1834 (Coleoptera: Curculionidae)

The histomorphology of the reproductive system and the germ cells has been useful to establish phylogenetic relationships in many insects. However, these elements remain little known in the Curculionidae. In this study, histomorphological structure of the male reproductive system of Tanymecus dilaticollis, which is economically important, is described, illustrated using stereomicroscopy, light microscopy, and scanning electron microscopy techniques, and discussed in relation to other Coleoptera species. Results showed that distinctive features of the male reproductive system of T. dilaticollis consist of a pair of yellowish testes, a pair of seminal vesicles, a pair of vasa deferentia, an ejaculatory duct, accessory glands, prostate glands, and aedeagus. Each testis is subdivided into two testicular follicles, enclosed by a peritoneal sheath. Each follicle of the mature testes is full sperm cysts with germ cells at various stages development of spermatogenesis. The testes have four types of germ cells (spermatogonia, spermatocytes, spermatids, and spermatozoa). They are occupied by the growth zone containing spermatogonia and spermatocytes, the maturation zone containing spermatids, while differentiation zone containing spermatozoa. There is a seminal vesicle at the center of each testis. Most mature sperms are stored in the seminal vesicle. Each testis is attached to the vas deferens by a stalk‐like seminal vesicle. In the distal part, vasa deferentia fuse with the ejaculatory duct. It is linked to the aedeagus. The provided results will contribute to the understanding of the reproductive cell biology of Curculionidae.     

Effect of a 2-month light cycle regimen on testicular parameters of adult Ile-de-France rams.

This experiment was conducted in Ile-de-France adult rams to examine the target point of a 2-month light cycle regimen on seminiferous tubule functions, on intertubular compartment and on Leydig cell parameters. Eight rams were subjected to a 2-month light cycle regimen and were compared to sexually active or inactive rams. In light-treated rams, testis weight was maintained equal or was higher than that of sexually active rams. Both tubular and intertubular tissues were found significantly higher in light-treated than in sexually active rams. The mean ratio of basement membrane area of the seminiferous tubules per Sertoli cells and the daily productions of A1 spermatogonia and of leptotene primary spermatocytes were significantly increased in light-treated rams as compared with sexually active or inactive rams. Meanwhile, the dairy productions of diplotene primary spermatocytes, of round spermatids, of spermatozoa and of the rete testis fluid were not significantly increased in light-treated as compared with sexually active rams but significantly greater than those of sexually inactive rams. Total volume, total numbers, and individual volumes of Leydig cells were at least equal or higher in light-treated than in sexually active rams.     

Morphological and histological structure of the male reproductive system of the water strider Gerris lacustris (Linnaeus 1758) (Gerridae,Heteroptera)

This work presents the male reproductive system morphology and histology of the water strider Gerris lacustris (Linnaeus 1758) (Gerridae, Heteroptera) using light microscopy and scanning electron microscopy. The male reproductive system of G. lacustris comprise of a pair of testes, two vasa deferentia, two seminal vesicles, an ejaculatory duct. There is no bulbus ejaculatorius and the long vas deferantia uniting to form a simple ductus ejaculatorius which is connected to the aedeagus. The testes are white colored and this cylindiric‐shaped structure lies along genital abdominal segment. The testicular follicles have three different development zones (growth zone, maturation zone, differentiation zone). Each testis has two follicles, which are not lined by a common peritoneal sheath and involving many cysts arranged in a progressive order of maturation from the distal to the proximal region; spermiogenesis occurs in mature males, finishing with the organization of sperm bundles. The testes are connected to the seminal vesicles, specialized sperm storage places, by the vas deferentia.     

太阳能空调蓄热水箱特性研究

根据南京地区的太阳辐射强度及典型建筑负荷的日变化规律,得出单位集热面积时可满足的负荷建筑面积及蓄热水箱温度变化规律;并对几种不同体积蓄热水箱进行了分季节的启动时间分析。结果表明,蓄热水箱体积影响着户式太阳能空调系统性能:夏季,在单位集热面积的情况下,水箱体积以70L为基准,体积增大114%,热水工作范围减小54%,可承担负荷减小25.2%,同时,体积增大到150L后启动时间也变为原来的2倍以上,可见,蓄热水箱体积越小越好,但它存在一个最小值随着日工作时间的延长而增大;冬季蓄热水箱体积对负荷的影响较小,但即使70L的水箱,冬季启动耗时也比夏季多4h。     

厦门大气可吸入颗粒物离子成分特征研究

采集厦门冬、春、夏三季大气颗粒物PM10，冬、夏两PM2．5样品，用IC进行离子成分分析，结果表明：厦门大气颗粒物水溶性离子成分呈春冬季高、夏季低的季节变化特征。二次离子SO4^2-、NO3^-与NH4^＋占PM10的近40％，海盐离子占7％；二次离子占PM2.5的48％，海盐离子占3％。二次离子污染是影响厦门环境空气质量的主要因子。     

Ultrastructural characteristics of the spermatogenesis during the four phases of the annual reproductive cycle of the black myotis bat,Myotis nigricans (Chiroptera: Vespertilionidae)

Myotis nigricans is an endemic species of vespertilionid bat, from the Neotropical region, that resembles temperate zone bats in their reproductive cycle; presenting an annual reproductive cycle with two periods of testicular regression, which are not linked to the apoptotic process and seems to be not directly linked to any seasonal abiotic variation. Thus, this study aimed to ultrastructurally evaluate their reproductive cycle. The process of testicular regression could be divided into four periods: active; regressing; regressed and recrudescence; with all presenting distinct characteristics. The active period was similar to that of other bats, presenting the complete occurrence of spermatogenesis, with three main types of spermatogonia (A_d, A_p, and B) and 12 steps in spermatid differentiation; however, it differed in having the outer dense fibers 1, 5, 6, and 9 larger than the others. These three types of spermatogonia undergo considerable morphologic changes from regressing to the regressed period, and in the recrudescence, they return to the basic morphology, which reactivates spermatogenesis. In conclusion, our study described the process of spermatogenesis, the ultrastructure of the spermatozoa and the distinct morphologic variations in the ultrastructure of the testicular cells of M. nigricans during the four different periods of its annual reproductive cycle. Microsc. Res. Tech., 76:1035–1049, 2013. © 2013 Wiley Periodicals, Inc.     

Morpho-anatomical characterization of some members of euglenophycota (algae) of north-east Punjab,Pakistan based on light microscopy (LM) and scanning electron microscopy (SEM)

The study was carried out in four districts, that is, Gujranwala, Gujarat, Narowal and Sialkot of Punjab, Pakistan. The sampling was carried out randomly in different seasons from the water bodies especially from wastewater. Twenty-one species belonging to Euglenophycota were identified using light microscopy and scanning electron microscopy from which 04 species belong to genus Phacus, 02 species belonging to Trachelomonas and Euglena based on light microscopy. It was observed that Euglena was the most diverse genus and it is supposed to be the indicator species of the polluted water. It was observed that E. oblonga was found in maximum pH range, that is, 7.0–11.0. Similarly, E. brevicaudatus was found in maximum EC, that is, 169 ± 1.5 ms/cm these outcomes indicated that for internal examination along with LM, SEM was necessary for correct identification of algal sample up to specie level.     

锦州市大气可吸入颗粒物中多环芳烃污染特征研究

为全面了解城市大气可吸入颗粒物污染状况,我们在2004年1、4、7、10四个月份采样四次,分别代表冬、春、夏、秋四个季节,对锦州市进行分季节采样,并对城市空气中可吸入颗粒物（PM10和PM2.5）中关国优先控制的16种多环芳烃（PAHs）进行了定量研究。结果表明,大气PM10和PM2.5中PAHs污染较重,且冬季高于其它季节,PAHs主要富集在PM2.5及以下细小颗粒物中。     

Marsupial morphology of reproduction: South America opossum male model

This study aims to describe the morphology of Didelphis sp. male genital organs (penis, testes, epididymis, ductus deferens, prostate, and bulbourethral gland). Ten male animals were used, eight for macroscopic and light microscopy analysis, and two for scanning electron microscopy. The testes and epididymis showed similarity to other eutherian mammals. The bifid penis showed the urethra ending in the medial region where the bifurcation begins, occurring in each segment extension of the urethral groove until the beginning of the glans. Histologically, the penis consists of a cavernous and spongy body, covered by stratified squamous epithelium with loose connective tissue. The urethra was lined by transitional stratified epithelium. In the prostate, prostatic segments were found consisting of tubular glands in a radial arrangement around the urethra, coated externally by a dense connective tissue associated with a relatively thick layer of smooth muscle arranged in two layers that surround the glandular tissue. The animals had three pairs of bulbourethral glands placed at the membranous and cavernous urethra junction with descending and parallel excretory ducts ending caudally in the urethral lumen. Microsc. Res. Tech. 76:388–397, 2013. © 2013 Wiley Periodicals, Inc.     

Differentiation of Leydig cells in the Mongolian gerbil

Information on postnatal Leydig cell (LC) differentiation in the Mongolian gerbil has been unavailable. Therefore, current investigation was designed to examine LC lineage differentiationin this rodent, from birth to adulthood. Gerbil testes at 1 day, 1–7 weeks (w), 2 and 3 months of age were conventionally processed by light and transmission electron microscopy. Immunocytochemistry for specific markers of steroidogenic enzymes, namely 3β‐hydroxysteroid dehydrogenase (3β‐HSD) and 11β‐hydroxysteroid steroid dehydrogenase 1 (11β‐HSD1) and also for androgen receptor (AR) was performed. The establishment of adult Leydig cell populations (ALC) during testis maturation in the gerbil follows the pattern previously described in other mammalian species, with the four progressive stages of differentiation. The LC progenitors were identified at second w by 3β‐HSD expression; the first newly formed ALC were recognized at fourth w whereas immature ALC appeared at fifth w. The latter were recognized by abundance of cytoplasmic lipid, in addition to expression of 11β‐HSD1 and intense nuclear AR immunoreaction. Mature ALC in gerbil exhibited irregular eccentric nuclei and a cytoplasmic canaliculus in the perinuclear area. Only one third of mature ALC in adult gerbils showed a high expression of 11β‐HSD1 and AR expression was highly variable among them. In conclusion, the process of differentiation of ALC population in gerbil follows the pattern previously established for other rodents. However, the resulting mature ALC are strikingly different due their singular asymmetric morphology and presence of a cytoplasmic canaliculus and as well as their functional heterogeneity. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.     

Ultrastructure of the bullfrog (Lithobates catesbeianus‐Shaw, 1802) oviduct in different seasons

The bullfrog (Lithobates catesbeianus) is an exotic animal that adapted perfectly to the climatic conditions of Brazil after introduction in the country. These climatic conditions favor the reproduction and fattening of bullfrogs. However, the development of the bullfrog is significantly reduced in colder regions because low temperatures affect the secretion of gonadotropins and change the sensitivity of the germinal epithelium to gonadotropic hormones. Thus, the temperature and photoperiod are abiotic factors that influence the life cycle of this species, especially with regard to reproduction. Samples from different regions of the oviducts (the infundibulum, magnum, and isthmus) of 9 bullfrogs were collected in the different seasons of the year. The samples were fixed and processed for analysis with scanning and transmission electron microscopy. A comparison of the morphology of the oviducts collected during different seasonal periods suggests that the frogs have greater reproductive potential in the spring due to the development of the structures related to the oviduct, presence of developed cilia, and electron‐dense granules. However, seasonal changes were noted in the animal throughout the year in preparation for reproduction during the spring and summer. Microsc. Res. Tech. 76:523–532, 2013. © 2013 Wiley Periodicals, Inc.     

Nickel nitrate: a new junction permeability tracer for the study of the blood-testis barrier.

With the purpose of evaluating a new intercellular tracer, nickel-K ferrocyanide, we compared results yielded by lanthanum with information provided by nickel. This was done in the seminiferous epithelium of Holtzman rats of several postnatal ages and in a wild local seasonal breeder Galea musteloides. Tissues were studied with transmission electron microscopy and freeze-fracture replications. Nickel tracing proved to delineate cell contours more intensely and less interruptedly than lanthanum. With regard to seasonal variations in adult galea, the limits of the barrier were similar to those described in other mammals: spermatogonia, preleptotene, and leptotene spermatocytes were surrounded by the tracer in the basal compartment. The zygotenepachytenes were contained in the lumenal compartment and tracers were stopped at the inter-Sertoli cell tight junctions. During the inactive spermatogenic phase in winter, the seminiferous epithelium contained Sertoli cells and occasional germ cells, never beyond the spermatocyte stage. The tracer filled intercellular spaces, indicating that the barrier was incompetent. Some resting germ cells showed nuclear hyperchromasia, karyolysis, organelle loss, cell shrinkage, and cell fusion leading to a multinucleated cells. The inter-Sertoli tight junctions were scanty and had randomly oriented and discontinuous junctional strands. Moreover, inter-Sertoli cell gap junctions proliferated. During the active spermatogenic phase in summer, junctions were numerous. Their junctional strands were parallel to each other, and continuous.     

Microstructural changes of CM186LC single-crystal superalloy during creep deformation at 750 °C

The microstructure of creep‐tested CM186LC Ni‐base single‐crystal alloy was studied to assess its suitability for use in the gas turbine environment. Creep tests were conducted at 750 °C and at stresses of 560 and 675 MPa up to 11 440 h. The microstructure of fractured and terminated specimens was investigated by light microscopy, scanning electron microscopy and analytical transmission electron microscopy. Microstructural analysis revealed the differences in the microstructure of creep‐tested CM186LC depending on the stress applied during creep at 750 °C.     

Hyperspectral interferometry: Sizing microscale surface features in the pine bark beetle

A new method of interferometry employing a Fabry–Perot etalon model was used to locate and size microscale features on the surface of the pine bark beetle. Oscillations in the reflected light spectrum, caused by self‐interference of light reflecting from surfaces of foreleg setae and spores on the elytrum, were recorded using white light hyperspectral microscopy. By making the assumption that pairs of reflecting surfaces produce an etalon effect, the distance between surfaces could be determined from the oscillation frequency. Low frequencies of less than 0.08 nm^?1 were observed in the spectrum below 700 nm while higher frequencies generally occupied wavelengths from 600 to 850 nm. In many cases, two frequencies appeared separately or in combination across the spectrum. The etalon model gave a mean spore size of 3.04 ± 1.27 μm and a seta diameter of 5.44 ± 2.88 μm. The tapering near the setae tip was detected as a lowering of frequency. Spatial fringes were observed together with spectral oscillations from surfaces on the exoskeleton at higher magnification. These signals were consistent with embedded multi‐layer reflecting surfaces. Possible applications for hyperspectral interferometry include medical imaging, detection of spore loads in insects and other fungal carriers, wafer surface and subsurface inspection, nanoscale materials, biological surface analysis, and spectroscopy calibration. This is, to our knowledge, the first report of oscillations directly observed by microscopy in the reflected light spectra from Coleoptera, and the first demonstration of broadband hyperspectral interferometry using microscopy that does not employ an internal interferometer. Microsc. Res. Tech. 78:873–885, 2015. © 2015 Wiley Periodicals, Inc.     

Bat intelligence search with application to multi-objective multiprocessor scheduling optimization

In this paper, we present the bat intelligence search for the first time. Bat intelligence is a novel and unique heuristic that models two major prey hunting behaviors of bats: (a) utilization of echolocation to observe the environment and (b) employment of constant absolute target direction approach to pursue preys. In order to illustrate the performance of bat intelligence, we implement this heuristic to solve two types of multiprocessor scheduling problems (MSP): single objective MSP and multi-objective MSP. In single objective MSP, we independently solve for minimization of makespan and minimization of tardiness. In multiple objective MSP, these two objectives are optimized simultaneously. In the single objective MSP, on average, the bat intelligence outperformed the list algorithm and the genetic algorithm by 11.12% when solving for minimization of makespan and by 23.97% when solving for the minimization of tardiness. In comparison to the genetic algorithm, the bat intelligence produces better results for the same computational effort. In multiple objective MSP, bat intelligence is combined with normalized weighted additive utility function to generate a set of efficient solutions by varying the weights of importance. The results demonstrate that the bat intelligence finds a set of Pareto optimal solutions on bi-objective optimization of MSP.     

Electron microscopic observation of the sagittal structure of Drosophila mature sperm

Observation of sperm development and determination of their morphological characteristics are very important to the understanding of phylogenetic relationships and the study of sperm function during fertilization. Although ultrastructural studies of sperm development in the testes of the fruit fly Drosophila have been performed, there are few reports describing electron microscopic morphology of mature sperm, that is, those released from the testes to the seminal vesicles. Here, we present the first report of the sagittal organization of Drosophila sperm head and neck regions by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The head and tail structures of a mature sperm, for example, the acrosome, nucleus, and flagellum, were easy to distinguish by the morphological characteristics of the sperm surface by SEM. The morphological relationships between the surface and internal structures of mature sperm were confirmed by observing longitudinal sections with TEM. Our approach overcame the technical difficulties involved in sample preparation for electron microscopic observation of the Drosophila mature sperm head, and therefore, this study serves as an important foundation for future genetic dissection of sperm ultrastructure and function in male sterile mutants. Microsc. Res. Tech. 77:661–666, 2014. © 2014 Wiley Periodicals, Inc.     

Quantitative analysis of mast cell structure

Fixed and embedded normal rat peritoneal mast cells were studied by light and electron microscopy, utilizing stereological methods to obtain quantitative data on their structure. The diameters of the mast cells and their nuclei averaged 10.9 and 5.8 μm respectively. The volume of the individual mast cell granule was estimated to 0.3 μm³. About 53% of the cytoplasmic volume was occupied by granules, and 2% by mitochondria. 11% of the cell volume was taken up by the nucleus. The average number of granules per cell was calculated to about 1020. Quantitative biochemical data on mast cells, extrapolated from the literature and applied to the calculated figures above, yield the following results with respect to mast granule contents-heparin: 95 × 10^?3 pg, histamine: 30 × 10^?3 pg and 5-hydroxytryptamine: 1.3 × 10^?3 pg per mast cell granule.     

Stereological estimation of average cell volume in monolayer culture by combined light and electron microscopy

In order to convert stereological ratio estimates into ‘absolute’ values (‘per cell’ values) the average cell volume must be estimated. The present paper describes a stereological method based on well-known point counting procedures for the estimation of average cell volumes in monolayer cultures fixed in situ. This method involves estimation of the average attachment area per cell by light microscopy combined with estimation of the attachment membrane surface density by electron microscopy. There is no need for any assumption as to cellular or nuclear shape. The method has been tested on an established cell line, NHIK 3025, and shows a good accuracy. It has also been used to analyse the volume changes that take place in human monocytes during monolayer culture, demonstrating a 28-fold increase of the average cell volume over 10 days.     

Histology and ultrastructure of the testis and vas deferens in Pseudochorthippus parallelus parallelus (Orthoptera,Acrididae)

Pseudochorthippus parallelus parallelus (Zetterstedt, 1821) (Orthoptera, Acrididae) is a widespread species in Europe, and also it is localized in some regions in Turkey such as Bursa, Eski?ehir, Ankara, Bolu, Düzce, and Çank?r?. The features of the reproductive organs such as the numbers and shapes of testes and follicles can be used as taxonomical characters. For this purpose, the ultrastructural and histological features of testis and vas deferens in P. parallelus parallelus were examined with using light microscope, scanning electron microscope, and transmission electron microscope. The mature P. parallelus parallelus has two conjugated testes produce spermatozoa. Each testis is composed of numerous testis follicles in which different stages of spermatogenesis and spermiogenesis develop. First, spermatocytes are formed by the mitosis division of the germ cells at the distal end of the follicles. Then, spermatocytes form spermatids by meiosis division in the middle region of the follicles. Finally, spermatids are differentiated to spermatozoa at the proximal region of the follicles. After maturation of the spermatozoa, sperm tails come together as the sperm bundles called as spermatodesm. Each follicle is connected to vas deferens via vas efferens to discharging spermatozoa. In spite of some differences, the testes and the vas deferens in P. parallelus parallelus are highly similar to the those of other species, especially Orthopteran species.