A comparative study of seven grabs used for sampling benthic macroinvertebrates in rivers

SUMMARY. After considering the large number of grabs described in the literature, seven grabs of weight < 25 kg were chosen for manual operation from a small boat: Van-Veen grab, weighted and unweighted Ponar grabs, Friedinger version of the Petersen grab, Dietz-La Fond mud-snapper, pole-operated Birge-Ekman grab and pole-operated Allan grab. Random samples (number of sampling units n= 10) were taken in a large tank with a known number of 2-mm cylindrical plastic pellets amongst stones of uniform size. Separate experiments were performed with four sizes of stones (model ranges: 2–4 mm, 8–16 mm, 16–32 mm, 32–64 mm). Stratified random samples (n= 10) were taken in rivers and the modal particle sizes at four sites were 0.004–0.06 mm, 0.5–2 mm, 16–64 mm and 64–128 mm. All grabs usually took a representative sample of the substratum at each site with no strong bias towards a particular particle size. The general performance of the Friedinger, Dietz-La Fond and Allan grabs was poor, except on a muddy bottom, with frequent failure to operate, small samples of substratum and a mean depth of penetration < 3 cm in all substrata except mud for the Dietz-La Fond and Allan grabs. The Van-Veen and Birge-Ekman grabs sampled to a mean depth < 3 cm in mud and fine gravel (2–4 mm), but the Birge-Ekman jammed frequently in fine gravel. Both Ponar grabs operated well and sampled to a mean depth ≥ 5 cm in mud and fine gravel, > 3 cm when small stones (8–16 mm) were present and 2 cm (weighted Ponar only) when larger stones (> 16 mm) were present in a gravel bottom. The mean depth was <0.8 cm for all grabs when larger stones (>16 mm) were predominant on the bottom. In the tank experiments with pellets, the efficiencies for the total catches of the Friedinger, Dietz-La Fond and Allan grabs were low with values <45% for fine gravel (2–4 mm), < 22% for small stones (8–16 mm) and <5% for a substratum of larger stones (>16 mm). If 50% is the minimum acceptable efficiency, then the Ponar, Van-Veen and Birge-Ekman grabs were adequate for fine gravel, only the two Ponar grabs were adequate for small stones and no grabs were adequate for sampling a substratum of larger stones (>16 mm). In field trials, the relative abundances of major taxa were similar for most grabs at each site; Friedinger and Dietz-La Fond grabs were the major exceptions. In terms of both mean number of taxa and mean number of invertebrates m^?2 the Ponar, Birge-Ekman and Allan grabs performed well on the predominantly muddy substratum at site 1, but only the weighted Ponar grab performed adequately on the predominantly gravel bottom with some large stones (>16 mm) at site 2. All grabs performed badly when larger stones (>16 mm) were predominant on the bottom (sites 3, 4). The relationship between the variances and means of the samples taken with each grab followed a power law for the catches of pellets in tank experiments, and for major taxa and total numbers at each site in field trials. Values of exponents in the power law lay within the range 1.14–2.34. The coefficient of variation was also frequently related to the sample mean and was an unreliable statistic for comparing the precision of grabs.     

Brief repot: Interactions with infants by full siblings,paternal half-siblings,and nonrelatives in a captive group of rhesus macaques (Macaca mulatta)

Six mother-infant pairs in a group of captive rhesus monkeys (Macaca mulatta) were observed for six months. “Infant grabs” by others and mothers' resistance to grabs were scored. More full siblings grabbed infants than either paternal half-siblings or nonrelatives. Mothers resisted grabbing by more nonrelatives than by paternal half-siblings. Although the maternal effect suggested by full sib-infant interactions is expected, the paternal effect revealed by mothers' tolerance of paternal half-sibs, but not full siblings, over nonrelatives is unexpected.     

Sampling performance of Ekman grabs — in situ observations and design improvements

The performance of five types of Ekman grab: the Birge-Ekman, the Kebo Lab-Ekman, the Hydro-Bios-Ekman, the Winnipeg-Ekmanand the Håkanson-Ekman, were examined in situ by SCUBA diving. Trials and observations are presented, and photographic documentation provided. Each type of grab often produced unrepresentative samples due to operation deficiencies. Tilting, brimming, and entry of sediment from outside the sample chamber, as well as redistribution, resuspension and loss of enclosed matter are the main biasing factors. Since the grabs under study are models in general use, these findings suggest that caution must be exercised when evaluating studies based on Ekman grabs of the usual design. Sampling reliability can be significantly improved by furnishing the grabs with a supporting stand and a mechanism which secures the lids during ascent. Tested designs for such devices are presented. A properly operated Ekman grab of adequate design is a suitable instrument for collecting certain types of samples such as benthic macrofauna, and infauna in particular.     

Making Forest of Bliss: The Film, the Book, the DVD, and the Breakthrough

Robert Gardner's and Àkos Östör's Making of Forest of Bliss (2002) is a combination book and DVD that contains eight teaching tools for better understanding Gardner's celebrated film Forest of Bliss. After the film was shot in 1985, filmmaker Gardner and anthropologist Östör recorded a conversation about each image and sound of the film while they screened it again in 1987, and remembered their filmmaking process on location in Benares, India. The feature length (89 minute) documentary about death ritual, reincarnation, the sacred Ganges River, and the very atmosphere of Benares is included as DVD, as are teaching tools such as frame grabs (still images from the film), a mathematically precise shot list, bibliography, important criticism and essays about the film, and the featured in-depth conversation between filmmaker Gardner and anthropological advisor Östör. This essay articulates the unique breakthroughs in pedagogy, cross-cultural studies, and multidisciplinary analysis such hybrid technology provides.     

Distribution, ecology and morphology of Lytocarpia myriophyllum (Cnidaria: Hydrozoa), a Mediterranean Sea habitat former to protect

In the Mediterranean Sea, as well as in other parts of the word, intense bottom trawling threatens deep and mesophotic assemblages, compromising mainly the survivorship of erect organisms and of the habitat complexity they shape. Protection of species able to affect their habitats, by increasing spatial complexity and enhancing interspecific interactions, is crucial for biodiversity conservation. It is urgent to highlight the occurrence of those species which act as ecosystem engineers and/or habitat former to enhance awareness on their ecological role and to develop focused conservation strategies. Lytocarpia myriophyllum is the largest Leptomedusan hydroid of the Mediterranean Sea, with colonies up to 1 m high, and the most abundant Aglaopheniid in the eastern part of the North Atlantic Ocean. This species creates wide forests on soft bottoms stabilizing sediments, providing refuge and food for several other associated organisms and could be defined both a habitat former and an ecosystem engineer. Thanks to trimix diving here we report on new insights on the morphological, biological and ecological features of L. myriophyllum meadows from the Mediterranean Sea furnishing a baseline for protection plans focused on these facies. This work demonstrates that direct studies of mesophotic habitats allow to collect far more detailed information than grabs, ROVs, or towed camera arrays and highlights the urgent need to redefine the vertical extension of several marine protected areas.     

Deciphering the Golgi apparatus: from imaging to genes

The Golgi apparatus is a vital organelle in eukaryotic cells. It grabs and processes secretory materials synthesized by the endoplasmic reticulum (ER) before sorting them to their destination. The Golgi also receives materials from vacuoles/lysosomes and the plasma membrane for further recycling to other compartments within the cell (1) (Figure 1). Given the vital role of the Golgi in a cell, it is important to understand how this organelle attains and maintains its structural and functional integrity during the intense processes of membrane traffic. Despite an equally central role of the Golgi in membrane traffic in eukaryotes, the organization of this organelle has some unique features in each cell system. Therefore, the wealth of information available on the structure and activity of the Golgi in one system is not always directly transferable to others. However, certain morphological and functional aspects are common among cell systems. Therefore, studying the factors that regulate organelle biogenesis and organization of the Golgi apparatus is important in basic cell biology of eukaryotes and may also contribute to a better understanding of how different cell systems have evolved. In this study, we report on the identification of Golgi mutants in plant cells. We have developed a screen that is a promising strategy not only for the identification of genes responsible for the morphological and functional integrity of the plant Golgi but could also provide fundamental information on other multicellular systems for which the power of forward genetics cannot be exploited as easily as in Arabidopsis.     

Key Features of Human Episodic Recollection in the Cross-Episode Retrieval of Rat Hippocampus Representations of Space

Neurophysiological studies focus on memory retrieval as a reproduction of what was experienced and have established that neural discharge is replayed to express memory. However, cognitive psychology has established that recollection is not a verbatim replay of stored information. Recollection is constructive, the product of memory retrieval cues, the information stored in memory, and the subject''s state of mind. We discovered key features of constructive recollection embedded in the rat CA1 ensemble discharge during an active avoidance task. Rats learned two task variants, one with the arena stable, the other with it rotating; each variant defined a distinct behavioral episode. During the rotating episode, the ensemble discharge of CA1 principal neurons was dynamically organized to concurrently represent space in two distinct codes. The code for spatial reference frame switched rapidly between representing the rat''s current location in either the stationary spatial frame of the room or the rotating frame of the arena. The code for task variant switched less frequently between a representation of the current rotating episode and the stable episode from the rat''s past. The characteristics and interplay of these two hippocampal codes revealed three key properties of constructive recollection. (1) Although the ensemble representations of the stable and rotating episodes were distinct, ensemble discharge during rotation occasionally resembled the stable condition, demonstrating cross-episode retrieval of the representation of the remote, stable episode. (2) This cross-episode retrieval at the level of the code for task variant was more likely when the rotating arena was about to match its orientation in the stable episode. (3) The likelihood of cross-episode retrieval was influenced by preretrieval information that was signaled at the level of the code for spatial reference frame. Thus key features of episodic recollection manifest in rat hippocampal representations of space.     

Identification and characterization of an endolysin encoded by the<Emphasis Type="Italic">Streptomyces aureofaciens</Emphasis> phage μ1/6

An open reading frame homologous to the genes encoding several cell-wall hydrolyzing enzymes was identified on the genome of actinophage mu 1/6. This open reading frame encoding the putative endolysin was amplified by polymerase chain reaction and cloned into the expression vector pET-21a. This gene consisted of 1182 bp encoding a 393 amino acid polypeptide with a molar mass of 42.1 kDa. The gene product was overexpressed in Escherichia coli, and then the lytic enzyme was purified by a two-step chromatographic procedure. When applied exogenously, the endolysin of phage mu 1/6 was active against all tested Streptomyces strains but did not affect other bacteria. The amino acid sequence showed a high homology with a putative amidase of the Streptomyces phase phi C31. Downstream of the endolysin gene, an open reading frame encoding an 88 amino acid protein was identified. Structural analysis of its sequence revealed features characteristics for holin.     

A Computer-Controlled Video System for Real-Time Recording of Insect Flight in Three Dimensions

A computer-controlled video system for real-time recording of insect flight in three dimensions is described. The flight paths of moths were recorded in a flight tunnel using two CCD cameras placed adjacent to each other at angles of 45 and 135° to the flight tunnel axis and separated by a distance of 120 cm. They were connected to two 2⁸-level gray-scale frame grabbers via two external synchronizers. The two-dimensional coordinates of the flying insect were obtained from the two cameras at 40-ms intervals and transferred to host computer for processing and monitor for real-time display. Due to speed limitation in the image acquisition hardware, construction of the three-dimensional file was carried off-line. The flying insect was rendered as a dark spot in a bright background using a homogeneous light source. As the insect enters into the field of view of the two cameras, the light distribution changes, and the frame grabber detects only those variation in the light distribution which results from a flying insect. The target insect can be as small as 3 pixels and can be tracked in a stereoscopic field of view 60 cm long and 50 cm high. A method was developed that allowed for scalar scoring of various pheromone sources to assess their attractiveness using vector flight parameters. This method was applied successfully for optimization of pheromone blend of the grapevine moth, Lobesia botrana.     

The Ends of Innocence: Conception and Seduction among the Daribi of Karimui and the Barok of New Ireland

Daribi sociality is elicited by a nasty truth about their world: women are sufficient unto themselves in a way men cannot be. Conception ideology precipitates the guilty knowledge that men's stake in society, as the second-best sex, is to redeem their deficient condition. Less strenuously motivating, Barok conception ideology comprises conventional images whose glosses are up for grabs so that knowledge or innocence are less matters of morals than of competence.     

Deletion mutants of herpesvirus saimiri define an open reading frame necessary for transformation.

Analysis of a 5,549-base-pair sequence at the left end of herpesvirus saimiri unique (L-) DNA revealed two open reading frames and genes for five small nuclear U RNAs (herpesvirus saimiri U RNAs). Replication-competent deletion mutants were constructed in order to assess the importance of these genetic features for transformation by this oncogenic herpesvirus. Although not required for replication, one of the open reading frames was found to be required for immortalization of marmoset T lymphocytes into continuously growing cell lines. The protein predicted by this reading frame (STP; saimiri transformation-associated protein) has a highly hydrophobic stretch of 26 amino acids sufficient for a membrane-spanning domain near its carboxy terminus; this domain is immediately preceded by a sequence appropriate for formation of a metal-binding domain (His X2 His X6 Cys X2 Cys, where Xs are other amino acids). One of two poly(A)+ RNAs that could encode STP is bicistronic, while the other has a long 5' untranslated region (approximately 1.5 kilobases). Although some analogies can be drawn between STP and LMP (lymphocyte membrane protein) of Epstein-Barr virus, STP is not related in sequence to LMP.     

半干旱黄土区苜蓿退化对坡面草本植物分布及多样性的影响

半干旱黄土丘陵区土壤水分亏缺引起人工苜蓿草地退化会显著影响其他草本植物的分布及多样性,然而地形驱动下的苜蓿草地退化及植被群落多样性响应还尚不清楚。以典型半干旱黄土丘陵区龙滩小流域为研究区,对不同地形条件下退化苜蓿草地地上生物量、草本多样性及生长季内0—200 cm土壤水分进行了定位监测,利用方差分析、相关分析和典范对应分析(CCA)明确坡面地形、苜蓿生长状况和土壤水分与其他草本植物分布及多样性之间的关系。结果表明:(1)地形显著影响植被群落特征,西坡、东坡和北坡样带苜蓿地上生物量明显不同,西坡和东坡样带中、下坡位苜蓿地上生物量明显高于上坡位,而其他草本的生物量、物种丰富度和多样性指数的变化趋势则与苜蓿相反;(2)苜蓿地上生物量与80—200 cm土壤水分显著正相关,而与0—20 cm和20—80 cm土壤水分的相关性较小;(3)地形特征、不同深度土壤水分和苜蓿地上生物量解释了退化苜蓿草地其他草本群落变异的87.8%,其中坡向、苜蓿地上生物量、0—20 cm和20—80 cm土壤水分4个因子解释了79.3%的群落变异。研究认为,半干旱黄土丘陵区不同地形条件引起坡面土壤水分变化,进而影响退化苜蓿草地地上生物量,使得苜蓿退化程度不同,而苜蓿退化程度和0—80 cm土壤水分决定了不同部位草本分布及多样性。     

The evolutionary origin of the 35 kb circular DNA of Plasmodium falciparum: new evidence supports a possible rhodophyte ancestry

In common with other Apicomplexan parasites, Plasmodium falciparum carries two extrachromosomal DNAs, one of which, the 6 kb element, is undoubtedly mitochondrial. The second, generally referred to as the 35 kb circle, is of unknown provenance, but the nature and organization of its genetic content makes a mitochondrial association unlikely and the molecule has features reminiscent of plastid genomes. We now report the occurrence on the circle of an open reading frame specifying a predicted 470 amino acid protein that shares more than 50% identity with a gene currently known only on the plastome of red algae. This high degree of conservation confirms the 35 kb circle's plastid ancestry, and we speculate that it may have originated from the rhodoplast of an ancient red algal endosymbiont in the progenitor of the Apicomplexa.     

The evolutionary origin of the 35 kb circular DNA of Plasmodium falciparum: new evidence supports a possible rhodophyte ancestry

In common with other Apicomplexan parasites, Plasmodium falciparum carries two extrachromosomal DNAs, one of which, the 6 kb element, is undoubtedly mitochondrial. The second, generally referred to as the 35 kb circle, is of unknown provenance, but the nature and organization of its genetic content makes a mitochondrial association unlikely and the molecule has features reminiscent of plastid genomes. We now report the occurrence on the circle of an open reading frame specifying a predicted 470 amino acid protein that shares more than 50% identity with a gene currently known only on the plastome of red algae. This high degree of conservation confirms the 35 kb circle's plastid ancestry, and we speculate that it may have originated from the rhodoplast of an ancient red algal endosymbiont in the progenitor of the Apicomplexa.     

Evaluation of a no-reference image quality metric for projection X-ray imaging using a 3D printed patient-specific phantom

PurposeFeasability of a no-reference image quality metric was assessed on patient-like images using a patient-specific phantom simulating a frame of a coronary angiogram.MethodsOne background and one contrast-filled frame of a coronary angiogram, acquired using a clinical imaging protocol, were selected from a Philips Integris Allura FD (Philips Healthcare, Best, The Netherlands). The background frame’s pixels were extruded to a thickness proportional to their grey value. One phantom was 3D printed using composite 80% bronze filament (max. thickness of 5.1 mm), the other was a custom PMMA cast (max thickness of 8.5 cm). A vessel mold was created from the contrast-filled frame and injected with a solution of 320 mg I/ml contrast fluid (75%), water and gelatin. Still X-ray frames of the vessel mold + background phantom + 16 cm PMMA were acquired at manually selected different exposure settings using a Philips Azurion (Philips Healthcare, Best, The Netherlands) in User Quality Control Mode and were exported as RAW images. The signal-difference-to-noise-ratio-squared (SDNR²) and a spatial-domain-equivalent of the noise equivalent quanta (NEQ_SDE) were calculated. The Spearman’s correlation of the latter parameters with a no-reference perceptual image quality metric (NIQE) was investigated.ResultsThe bronze phantom showed better resemblance to the original patient frame selected from a coronary angiogram of an actual patient, with better contrast and less blur than the PMMA phantom. Both phantoms were imaged using a comparable imaging protocol to the one used to acquire the original frame. The bronze phantom was hence used together with the vessel mold for image quality measurements on the 165 still phantom frames. A strong correlation was noted between NEQ_SDE and NIQE (SROCC = –0.99, p < 0.0005) and between SDNR² and NIQE (SROCC = –0.97, p < 0.0005).ConclusionUsing a cost-effective and easy to realize patient-specific phantom we were able to generate patient-like X-ray frames. NIQE as a no-reference image quality model has the potential to predict physical image quality from patient images.     

竹亚科簕竹属毛凤凰竹繁殖器官的补充描述

《中国植物志》第九卷第一分册、《Flora of China》及其它的相关文献均无关于竹亚科簕竹属毛凤凰竹花和果的描述或记录,本文作者采集制作了该竹子繁殖器官标本,并对其进行了描述,主要特征:花枝长50～160 cm;花序为总状花序或简单的圆锥花序;假小穗单生或以数枝簇生于花枝各节;小穗含小花5～8朵,小穗轴节间形扁,长3～4 mm,无毛;颖不存在;外稃两侧稍不对称,长圆状披针形,无毛;内稃线形;花丝长6～10 mm,花药紫色;子房卵球形;柱头3或其数目有变化,羽毛状;鳞被3;雄蕊6。花期3～4月。成熟颖果为细狭的长圆形,长0.8～1.0 cm,直径2.0～2.5 mm,棕褐色,果皮较厚。花标本采自厦门市园林植物园竹类植物区。     

FTIR studies of internal proton transfer reactions linked to inter-heme electron transfer in bovine cytochrome c oxidase

FTIR difference spectroscopy is used to reveal changes in the internal structure and amino acid protonation states of bovine cytochrome c oxidase (CcO) that occur upon photolysis of the CO adduct of the two-electron reduced (mixed valence, MV) and four-electron reduced (fully reduced, FR) forms of the enzyme. FTIR difference spectra were obtained in D(2)O (pH 6-9.3) between the MV-CO adduct (heme a(3) and Cu(B) reduced; heme a and Cu(A) oxidized) and a photostationary state in which the MV-CO enzyme is photodissociated under constant illumination. In the photostationary state, part of the enzyme population has heme a(3) oxidized and heme a reduced. In MV-CO, the frequency of the stretch mode of CO bound to ferrous heme a(3) decreases from 1965.3 cm(-1) at pH* 相似文献   

The biological standard of living in pre-modern Korea: Determinants of height of militia recruits during the Chosŏn dynasty

This paper extends the research on the biological standard of living in the Korean peninsula back to pre-modern times. Drawing on militia rosters of the Chosŏn Dynasty from the sixteenth to eighteenth centuries, we tentatively conclude that the final height of Korean men during this period was 166 cm and thus slightly above that of modern North Korean men (165 cm). On the other hand, the average height of modern South Korean men is 172 cm, 6 cm more than what we tentatively estimate for pre-modern Korean men. Regression analysis of the height of pre-modern Korean men finds that un-free Koreans (“slaves”) were significantly shorter by about 0.6–0.7 cm than commoners, whereas the average height of recruits suffering from smallpox did not differ significantly from that of other recruits. Moreover, regional, as opposed to birth-dummy, variables account, and to a significant degree, for most of the differences in height. Whether or not this is a result of socioeconomic differences across provinces or a result of other regionally-varying factors remains an open question.     

The primary structure of a halorhodopsin from Natronobacterium pharaonis. Structural, functional and evolutionary implications for bacterial rhodopsins and halorhodopsins

We cloned and sequenced the gene coding for the polypeptide of a halorhodopsin in Natronobacterium pharaonis (named here pharaonis halorhodopsin). Peptide sequencing of cyanogen bromide fragments, and immunoreactions of the protein and synthetic peptides derived from the COOH-terminal gene sequence, confirmed that the open reading frame is the structural gene for the pharaonis halorhodopsin polypeptide. The flanking DNA sequences, as well as those for other bacterial rhodopsins, were compared to previously proposed archaebacterial consensus sequences. In pairwise comparisons of the open reading frame with DNA sequences for bacterio-opsin and halo-opsin from Halobacterium halobium, silent divergences (mutations/nucleotide at codon positions which do not result in amino acid changes) were calculated. These indicate very considerable evolutionary distance between each pair of genes. In spite of this, the three protein sequences show extensive similarities, indicating strong selective pressures. Conserved and conservatively replaced amino acid residues in all three proteins identify general features essential for ion-motive bacterial rhodopsins, responsible for overall structure and chromophore properties. Comparison of the bacteriorhodopsin sequence with those of the two halorhodopsins, on the other hand, identifies features involved in their specific (proton and chloride ion) transport functions.     

Measurement of Horizontal and Vertical Movement of Ralstonia solanacearum in Soil

Two model systems were constructed to measure horizontal and vertical movement of bacteria in soil. These systems were applied to measuring movement of Ralstonia solanacearum (race 1, biovar 3), a causal agent of bacterial wilt of tomato, in andosol and sand at 28°C. The first system was used to measure horizontal movement of the bacteria in soil packed in a narrow horizontal frame. Suspension of the pathogen was applied to soil at one end of the frame, and bacterial number per gram of soil was measured over distance from the inoculation point after 4 days. Horizontal movement of R. solanacearum in supersaturated soil, but without flow, was possibly due to diffusion and the front advanced at 2.2 cm/day in andosol, and at 8.1 cm/day in sand. Using the same experimental system, but applying water inflow to one end of the frame only, the bacterium was detected at the front of water in andosol and sand. The front of the distribution advanced at 20.4 cm/h in andosol and 66.3 cm/h in sand. In the second experimental system, a cylinder of soil packed in a short tube was soaked with water, and soil at the top of the tube was inoculated with bacterial suspension. Immediately, soil cylinders were turned upward, and the bacterial number per gram of soil was measured along vertical distance from the inoculation point after 7 days. Using the system with andosol, the capillary water front rose to 32.5 cm over 7 days after inoculation, and R. solanacearum reached to 18.8 cm height. In sand, capillary water rose to 20.0 cm and the bacteria reached to 16.3 cm height.