Reconstructing 20th century flood patterns in Havasu Creek, Arizona, using historical and dendrochronologic data [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Havasu Creek is the second largest tributary of the Colorado River in Grant Canyon. Perennial streamflow in the creek seldom exceeds 2 cubic meters per second, but it supports an important riparian habitat as well as unique travertine pools and waterfalls that attract over 20,000 tourists annually. Havasu Canyon is also home to over 400 members of the Havasu Tribe. Despite a long history of habitation and recreation in Havasu Canyon, streamflow records for Havasu Creek are extremely limited, making flood prediction difficult.

改变土壤碳输入对我国北方温带草原土壤碳、氮库和碳、氮循环的影响

土壤是陆地生态系统最重要的碳库和氮库，在陆地生态系统碳氮循环过程中起着举足轻重的作用。植物光合作用产物向地下的分配(根系分泌、细胞凋亡和根系分解)和地上凋落物分解是土壤碳两个最主要的来源，关于这两种碳输入途径和量如何影响陆地生态系统土壤碳氮库和循环的有限理解，限制了我们预测陆地生态系统碳循环对于全球气候变化的响应和反馈。本实验以我国北方广泛分布的温带典型草原生态系统为研究对象，通过添加和去除地面凋落物以及割草改变植物对土壤的碳输入途径和量，观察温带草原土壤有机碳库和氮库各个组分(微生物生物量碳氮、活性碳、可溶性碳、轻重组碳、总有机碳、总有机氮)及碳氮循环(微生物呼吸、土壤呼吸、生态系统气体交换、净氮矿化)的变化，来区分和量化凋落物分解和根系分泌、分解这两种碳输入方式对草原土壤碳库和循环的相对贡献和影响，有助于揭示在全球变化背景下温带典型草原生态系统碳库和碳循环的响应机制，并为预测其未来变化动态以及对全球气候变化的反馈提供参数估计和模型校正和验证。 我们对各处理样方土壤温度、土壤水分以及土壤呼吸进行了一个生长季的测定，结果表明，添加和去除凋落物都使得土壤呼吸与对照相比都有所增加，但是都没有达到显著水平;而无论地上凋落物的量添加、去除还是不变，植物光合作用对土壤呼吸的影响则比较显著，去除植物显著地降低了土壤呼吸。这说明处理一年后，植物对土壤呼吸起主导作用，而凋落物处理对土壤呼吸的影响还需要更长时间的观察。此外，生物量的结果也表明了地上凋落物的改变会影响到植物生长，从而影响到植物对土壤的碳输入，但是都没有达到显著水平，仍然需要我们进行更长时间的处理和观察。 通过在生长季前期、中期、后期进行了三次氮矿化的测定，以及在生长季后期进行了一次微生物生物量测定，我们得出以下结论：添加凋落物加快了净氮矿化速率，但是没有达到显著影响水平;同样，去除凋落物降低了净氮矿化速率，也没有达到显著水平。此外，添加凋落物处理微生物生物量碳、氮都有所增加，与对照相比没有显著差异，但是显著高于另外几个处理。 通过本研究，我们对于根系分泌和地上凋落物分解这两种碳氮输入途径对我国温带草原碳氮循环的影响有了初步的了解。与森林生态系统相比，由于草原生态系统土壤碳氮含量低，土壤碳库和转化对碳输入途径和量的变化更为敏感，在处理第一年，土壤微生物量和土壤呼吸都发生了显著的变化。然而，由于改变土壤碳库是长时间日积月累的结果，草原生态系统某些指标对碳输入途径和量的变化的响应还需要较长时间才能显示出来，例如添加和去除凋落物虽然使得土壤呼吸值有所增加，但是还都没有达到显著的水平;另外碳输入途径和量的变化对草原生态系统氮矿化还没有产生显著的影响。这些都需要更长时间的处理和观测来验证。

Aquacrops of Darbhanga District in north Bihar and their commercial significance

Darbhanga district in North Bihar is characterised by thick alluvial soil, moderately good rainfall, high humidity, ample sunshine and numerous water resources in the form of perennial rivers, tributaries, streams, lakes, ponds, pools and puddles. The aquacrops of this district include several species of commercially important fishes, aquatic cash crops such as makhana (Euryale ferox), singhara (Trapa spp.), lotus, lilly, Khubi etc. and molluscs. This paper highlights the commercial significance of these aquacrops and offers suggestions for their sustained development.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 1. Preliminary report: introduction and description of the stations

The Austrian-Ceylonese hydrobiological mission of 1970 investigated and made collections from 36 flowing water systems (brooks, torrents, rivers); of these, 34 water systems were in the mountains regions of south-west and south-east of Sri Lanka. In the crystalline mountain region, the water systems are extremely poor in electrolytes, very soft and slightly acid; these torrential streams have strong falls, high flow velocities and boulder bottoms. The water temperatures increase from the sources and brooks at 2,000 m altitude to the mouths from 15°C to 28°C. The density of animal population (macro and meso-fauna) increases from the river bank regions (and pools) towards the sections with strong current and reaches on the rocks in the cascades a density of 500 to appr. 750 individuals/1/16m².

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute University of Vienna (Austria) and the Department of Zoology of the University of Ceylon, Vidyalankara Campus, Kelaniya (Sri Lanka). Pt 17. The freshwater gastropods of Ceylon

In the present study the specimens collected by the Austrian-Ceylones hydrobiological mission 1970 are described. The freshwater gastropods in this study were collected from 100 different localities, mostly running waters, but some were also collected from stagnant waters like pools, irrigated paddy fields, swamps and water reservoirs (tanks). Listed from these localities are 31 species (and subspecies) 28 species are Streptoneura (=Prosobranchia), 3 species are Euthyneura-Pulmonata Basommatophora.

Report of the marine work at Hopkins Marine Station, Pacific Grove, California during the six-week period from June 25 to August 5, 1938

The primary objective in doing this work was to become acquainted with as many forms as possible of the marine fauna of the intertidal zone and if possible to determine some of the environmental relationships which exist in as many different types of habitats as possible. Due to limited amount of time spent in this study no very intensive work could be done and only a general survey was made of the more conspicuous forms of life which were encountered. Most of the work consisted of collecting and observing animals in the tide pools during periods of low tides. The animals collected were then taken to the laboratory and observed and determined as to species. Notes were taken as to place, time, and situation under which the animals were found. As many different types of habitats as possible were visited which included rocky intertidal areas of Mussel Point, Point Pinos, Lighthouse Point, Pescadero Point and Carmel Point just east of Carmel Beach. Sandy beaches were visited at Monterey Beach, Carmel Beach and Asilomar Beach. A marine estuary habitat was visited at Elkhorn Slough. More than two hundred species were identified and observed during this six-week period. A rather hasty population study was made of the eelgrass, Phyllospadix, of the intertidal zone at Mussel Point and of an algae, Gigartina caniculata, which grows at the level just above the eelgrass.

Mitochondrial DNA variation, effective female population size and population history of the endangered Chinese sturgeon, Acipenser sinensis

The anadromous Chinese sturgeon (Acipenser sinensis), mainly endemic to the Yangtze River in China, is an endangered fish species. The natural population has declined since the Gezhouba Dam blocked its migratory route to the spawning grounds in 1981. In the near future, the completion of the Three Gorges Dam, the world's largest hydroelectric project, may further impact this species by altering the water flow of the Yangtze River. Little is currently known about the population genetic structure of the Chinese sturgeon. In this study, DNA sequence data were determined from the control region (D-loop) of the mitochondrial genome of adult sturgeons (n = 106) that were collected between 1995-2000. The molecular data were used to investigate genetic variation, effective female population size and population history of the Chinese sturgeon in the Yangtze River. Our results indicate that the reduction in abundance did not change genetic variation of the Chinese sturgeon, and that the population underwent an expansion in the past. AMOVA analysis indicated that 98.7% of the genetic variability occurred within each year's spawning populations, the year of collection had little influence on the diversity of annual temporary samples. The relative large effective female population size (N-ef) indicates that good potential exists for the recovery of this species in the future. Strikingly, the ratio of N-ef to the census female population size (N-f) is unusually high (0.77-0.93). This may be the result of a current bottleneck in the population of the Chinese sturgeon that is likely caused by human intervention.

Phylogeny of mitochondrial DNA macrohaplogroup N in India, based on complete sequencing: Implications for the peopling of South Asia

To resolve the phylogeny of the autochthonous mitochondrial DNA (mtDNA) haplogroups of India and determine the relationship between the Indian and western Eurasian mtDNA pools more precisely, a diverse subset of 75 macrohaplogroup N lineages was chosen fo

The survey on growth and survival rate parameters with slurry and comparison by common method

This project was on “Study of Slurry, as an enrichment compound, on growth and survival parameters of Rutilus firisii kutum Kamensky 1901 larva and compare with routine condition according to hypothesis that use of Slurry, fertile organic compound, to increase the efficiency of survivorship and growth of Rutilus firisii and in other hand adaptation of natural food was performance.” The object of this project is to compare growth of Rutilus firisii and in usual condition and the condition of use Slurry The experiences performed in culture and propagation center Dr. Yousefpour decent (Associan of Dr. Beheshti culture and propagation) in Siahkal village, 32 Km far from southeast, in North of Iran. In this plan, three different treatments and related these nine pools , in 1.7 hec area (in same condition) were determined so that the density of storage was 1.7 million/hec larva. In this research at first treatment m we use slurry as enrichment compound during larval within a period of 13 days, and it used all the days of during larval in second treatment. Then the result of this study compared to control treatment. The results have shown the level of this study compared to control treatment. The results have shown the level of survivorship in pools were nutrition by slurry was 1.7 million times or twice than pools were nutrition with usual concentrate. In addition, growth coefficient such as daily weight growing (DWG) index, daily length growth (DLG), specific growth ratio (SGR) were measured in this case. All of these parameters in slurry treatment were shown noticeable enhancement in first treatment Thereof in the first week there was significant difference (P<0.001) between the average of length and weight in first week , and in the second week there was a significant difference (P<0.05) between them.

Examining the possibilty of multiplication and breeding of (Schizothorav [sic] zarudnyi) in order to restoration of regional aquatics reservations of Hamoon Lake and taking its advantag [sic] for aquaculture

Schizothorax zarudnvi, is an endemic fish of east country waters. (Triple lagoons of Hamoon and relevant water resources) that in the world it is reported in this resource specially. This fish named Hamoon mahi is one of the most economically valuable species in this region. Because of the recent years droughts, Hamoon logoon has been drive since 2000. Also, semi-wells (a semi natural resource) were affected drastically by recent drought years and their volume reduced to nearly one third of their real volume and resulted in changing at growth and reproduction physiology process in Schizothorax zanidnyi, brood stocks. Beginning of this project was done from October 2003. It's field studies begun (brood catching) since November 2001 by two methods including entangling gairs and at semi wells of Sistan that (Beach seine) had maximum rate of preparing qualified brood stocks. Broods transferred to Cyprinidea reproduction work shop of Zahak and after taking primary measures they stored in to the edaphic pools. Increasing the success safety factor (coefficient) for artificial reproduction of Sthizothorax zarudnyi , identifying the appropriate tune for Hormonal acceptance (physiological preparation of broods) is needed , so this important work was done regularly by histological studies and GSI measurements since November. Highest GSI rates of females (%80.51) and highest IV stage abundance of sexual maturity (%l 00) were observed an march. On the base of this date, Hormone therapy was done on broods on march. The used hormones are as follows Hypophysis. extraction, GnRHa and Anti Dopamin at the dozes of 3-6 ml, 20-30kg and 10-15 ml per kg body weight respectively and 2-3 times from 11-12-80 they were injected. Injected broods kept in to two circumstances, flow-through (rounded pool) and stagnant systems. In stagnant system 14 and 19 individuals of female and male (Schizothorax zauiulnri) broods, respectively injected in 11th, 15111, 19th, and 24th of march 1380. Non of the injected broods in 11 and 15 and 19th march (in stagnant Condition) answered to Hormone therapy. After final injection broods had general less activity and a few of them died. Mean temperature of brood pond waters (daily) which were injected. Fluctuated between 10-25-13. 63°c but injected broods on 24th march had different characteristics. They had pale color and had few fecundity. In this stage of injection they hadn't any successful vulation. After injection, Mean daily water temperature was 15, 88-17, 54°c. In Flowing system, 13-16 individual of males and females respectively were injected on 15th, 19th, 22th and 23th march. None of injected producers on 15th and 19th march with mean daily water temperature of 10, 25-12°c were prepared for spawning but injected producers on 22nd an 23th march with mean daily water temperature of 13.5-1 rc responded about 75-100 percent. (Schizothorax zarudnyi) brood stocks were prepared for spawning after 353-428 hours/day from final injection. Diameter of obtained eggs (before fertilization) was between 1.9-2.3 min and of fertilized eggs was 3.8mm. Fertilized eggs of (Schizothorax zarudnyi) were hatched after 6-7 days with mean water temperature of 17.08°c. Mean length of on one day larvae was 9.47 mm. Larvae was 9.47 mm. Larvae adsorbed the whole yolk sac after , 5-6 days at 17- 1°c and were prepared for releasing in to edaphic pools. Because of the lack of necessary and complementary facilities in the region , they had to release them in to veniros and growing them for 8 days. At the end of 18th day , 35000 larvae (at first) released into an edaphic pond with a volume of 150m2. After growing them for one moth , mean length and weight of new hatched larvae was 29.41 mm and 1.12►r , respectively. With respect to results of this investigation , artificial reproduction of (Schizothorax zarudnyi) Can be possible at 14-17°C and flowing water with Hormonal treatment. It -s breeding has increased development than other cultural specious in the region. Due to high economical value of this specious in Sistan and ti-s specialization east waters of Iran and having high resistance and proper growth There is a need of it's development and reproduction and culture in fish culture fanns (edaphic ponds• two-purpose pools) at the region and country.

The response of buildings to tunnelling: A case study

A case study of the response of two buildings to the construction of a 12 m diameter tunnel excavated by conventional method, in Italy, is studied. The 12 m diameter tunnel was constructed carrying out reinforcement of the tunnel face and around the crown prior to excavation and installation of the temporary sprayed concrete lining and the permanent reinforced concrete lining. Reflective prisms, placed at first floor level around the perimeter of the building facades, allowed building settlements to be measured. Ground settlements between the two buildings were measured using BRE type settlement studs. Extensive protective measures were adopted to maintain stability of the tunnel excavation and to reduce ground movements. The number of horizontal jet grout columns installed into the tunnel face was reduced over the course of the project. Results from CPT tests indicate that the undrained shear strength at the tunnel axis is around 120 kPa. SPT and undrained unconsolidated (UU) triaxial tests indicate lower strengths of around 80 kPa, although this may be due to sample disturbance.

Wetlands and riparian zones as buffers and critical habitats for biotic communities in Lake Victoria

Despite their ecological and socio-economic importance, Lake Victoria's adjoining "swamps" and lake interface are among the least investigated parts of the lake. The "swamps" a term commonly equated to "wastelands" and the difficult working environment they present in comparison to open water, are major factors for the low level of attention accorded to shoreline wetlands. Moreover, definitions of wetlands highlighted for example in the Ramsar Convention as "areas of marsh, fern, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh or brackish, or salt, including areas of marine water, the depth of which does not exceed six metres" (Ramsar, 1971) were designed to protect birds (water fowl) of international importance. The Ramsar definition, which also includes oceans, has till recently been of limited use for Lake Victoria, because itdoes not fully recognise wetlands in relation to other public concerns such as water quality, biodiversity and the tisheries that are of higher socioeconomic priority than waterfowl. Prior to 1992, fishery research on Lake Victoria included studies of inshore shallow habitats of the lake without specific reference to distance or the type of vegetation at the shore. Results of these studies also conveniently relied heavily on trawl and gill net data from the 5-10 m depth zones as the defining boundary of shallow inshore habitats. In Lake Victoria, such a depth range can be at least one kilometre from the lake interface and by the 10m depth contour, habitats are in the sub-littoral range. Findings from these studies could thus not be used to make direct inferences on the then assumed importance of Lake Victoria wetlands in general.

Observations on the biology of Nothobranchius guentheri (Pfeffer) (Cyprinodontidae), an annual fish from the coastal region of East Africa

Nothobranchius guntheri is found in seasonal pools and streams in the coastal region of Tanzania. A population recurring annually in a pond near Kilosa has been studied. Growth in length was rapid and maximum mean lengths were attained within 11-12 and 7-8 weeks of hatching by males and females respectively. Males grew larger and exhibited wider variation in length than females. N. guentheri shows clear sexual dichromatism. No significant inequality in the sex ratio was found. Females with ripe eggs were found 7-8 weeks after hatching. Spawning continued throughout adult life and fecundity increased markedly with increasing length. In laboratory aquaria, aggressiveness between adult males was noted and females were actively driven on to the substratum preparatory to spawning. The diet of the fish pond consisted chiefly of aquatic and terrestrial insects, of which midge larvae and pupae were the most common. N. guentheri is exploited by man in the aquarist trade and for the biological control of mosquitoes. An extended redescription of the species is appended which includes N. melanospilus (Pfeffer) as a synonym.

La reproducción de la merluza en el Mar Argentino (Merlucciidae, Meluccius merluccius hubbsi) : 1. Descripción histológica del ciclo del ovario de merluza

The present paper deals on the histological description of the hake ovary made on the basis of gonad observations of 394 females during the period April 1966 March 1967. The material was obtained from weekly sampling of commercial catches carried out at the Institute of Marine Biology (Prov. Buenos Aires, Argentina). The anatomical and histological description of the standard ovary and the adopted terminology are given. The maturation process is divided into five periods, from ovocyte formation to yolked ovocyte formation, with its histological description. Ovary changes are analyzed on detail. The following conclusions were outlined: 1. Analysis demonstrated that although some specimens were totally spawned others, at the end of the spawning period, retaining a great number of ovocytes in different maturity stages. Therefore, postspawners have been classified as follows: Postspawned II : This stages is characterized by the empty ovarian structure, with ovocytes in stage II, which will remain in the resting phase untill next spawning season. Postspawned III and IV: Their main characteristics are: tissue destruction, bloody residuals and remaining ovocytes in stage III and IV, respectively. 2. Some transformations were found in ovaries of postspawned III and IV. They are classified as follows, according to its origin and structure: Developed from follicular cell membrane – a) Glandular formations, b) Epiteloid formations - Originated from remaining ovocytes, c) Ovocyte disintegration, d) Ovocyte with follicular cell infiltration. 3. All those structures derived from postpawners III and IV have a temporary character and will be reabsorbed. Their presence delay the recuperation of the organ and its reproductive functions. Consequently, the possibility of those structures acting as control mechanisms is suggested. 4. Transformations pointed out in paragraph Nº 2 prevent the possibility of consecutive spawning originated from the remaining ovocytes (II and IV). 5. No structures originated from postspawners III and IV were found during summer season. 6. Reproductive cycle of hake has been described monthly. It was observed that maturing ovaries predominate in summer (November-December).

Visuomotor feedback gains upregulate during the learning of novel dynamics.

At an early stage of learning novel dynamics, changes in muscle activity are mainly due to corrective feedback responses. These feedback contributions to the overall motor command are gradually reduced as feedforward control is learned. The temporary increased use of feedback could arise simply from the large errors in early learning with either unaltered gains or even slightly downregulated gains, or from an upregulation of the feedback gains when feedforward prediction is insufficient. We therefore investigated whether the sensorimotor control system alters feedback gains during adaptation to a novel force field generated by a robotic manipulandum. To probe the feedback gains throughout learning, we measured the magnitude of involuntary rapid visuomotor responses to rapid shifts in the visual location of the hand during reaching movements. We found large increases in the magnitude of the rapid visuomotor response whenever the dynamics changed: both when the force field was first presented, and when it was removed. We confirmed that these changes in feedback gain are not simply a byproduct of the change in background load, by demonstrating that this rapid visuomotor response is not load sensitive. Our results suggest that when the sensorimotor control system experiences errors, it increases the gain of the visuomotor feedback pathways to deal with the unexpected disturbances until the feedforward controller learns the appropriate dynamics. We suggest that these feedback gains are upregulated with increased uncertainty in the knowledge of the dynamics to counteract any errors or disturbances and ensure accurate and skillful movements.