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Lake Griffin received discharges for decades from muck farms developed on former floodplain wetlands, leading to hypereutrophic conditions. Management actions included wetland restoration of farmland to reduce nutrient discharges, and harvesting of gizzard shad to remove nutrients in fish biomass and reduce nutrient recycling from sediments. Despite a reported susceptibility to wind-driven sediment resuspension, there have been substantial improvements in water quality in Lake Griffin, including decreases in nutrient concentrations, chlorophyll- a , and cyanobacterial biovolume, and increases in water transparency. Water quality improvements in Lake Griffin were substantially greater than occurred in ten comparison lakes. External nutrient load reduction was the primary factor contributing to water quality improvement, although there was evidence of an effect of shad harvesting, including correlations between shad catch per unit effort and nutrient concentrations, and an estimated effect of biomass removal and recycling reduction accounting for about 40% of the external load during the harvest period. Net production of total nitrogen in the lake was strongly related to external total phosphorus loading, indicating phosphorus limitation of nitrogen fixation. The response of Lake Griffin indicates that the combination of external nutrient load reduction and biomanipulation can result in sustained improvements in water quality in shallow subtropical lakes.

First published in 1937, this is a collection of ten stories \"about a boy named Bertram who goes on adventures that involve fantastical animals\"-- Provided by publisher.

Over the past three decades, we have witnessed one of the great revolutions in our understanding of the cosmos-the dawn of the Exoplanet Era. Where once we knew of just one planetary system (the solar system), we now know of thousands, with new systems being announced on a weekly basis. Of the thousands of planetary systems we have found to date, however, there is only one that we can study up-close and personal-the solar system. In this review, we describe our current understanding of the solar system for the exoplanetary science community-with a focus on the processes thought to have shaped the system we see today. In section one, we introduce the solar system as a single well studied example of the many planetary systems now observed. In section two, we describe the solar system's small body populations as we know them today-from the two hundred and five known planetary satellites to the various populations of small bodies that serve as a reminder of the system's formation and early evolution. In section three, we consider our current knowledge of the solar system's planets, as physical bodies. In section four we discuss the research that has been carried out into the solar system's formation and evolution, with a focus on the information gleaned as a result of detailed studies of the system's small body populations. In section five, we discuss our current knowledge of planetary systems beyond our own-both in terms of the planets they host, and in terms of the debris that we observe orbiting their host stars. As we learn ever more about the diversity and ubiquity of other planetary systems, our solar system will remain the key touchstone that facilitates our understanding and modeling of those newly found systems, and we finish section five with a discussion of the future surveys that will further expand that knowledge.

Fluxes of dissolved and particulate nitrogen (N) and phosphorus (P) from three adjacent watersheds were quantified with a high-resolution sampling program over a five-year period. The watersheds vary by an order of magnitude in area (12,875, 7968 and 1206 ha), and in all three watersheds intensive agriculture comprises > 90% of land. Annual fluxes of dissolved N and P per unit watershed area (export coefficients) varied ∼2X among watersheds, and patterns were not directly related to watershed size. Over the five-year period, mean annual flux of soluble reactive P (SRP) was 0.583 kg P· ha-1· yr-1 from the smallest watershed and 0.295 kg P· ha-1· yr-1 from the intermediate-sized watershed, which had the lowest SRP flux. Mean annual flux of nitrate was 20.53 kg N· ha-1· yr-1 in the smallest watershed and 44.77 kg N· ha-1· yr-1 in the intermediate-sized watershed, which had the highest nitrate flux. As a consequence, the export ratio of dissolved inorganic N to SRP varied from 80 (molar) in the smallest watershed to 335 in the intermediate-sized watershed. Because most N was exported as nitrate, differences among watersheds in total N flux were similar to those for nitrate. Hence, the total N:P export ratio was 42 (molar) for the smallest watershed and 109 for the intermediate-sized watershed. In contrast, there were no clear differences among watersheds in the export coefficients of particulate N, P, or carbon, even though > 50% of total P was exported as particulate P in all watersheds. All nutrient fractions were exported at higher rates in wet years than in dry years, but precipitation-driven variability in export coefficients was greater for particulate fractions than for dissolved fractions. Examination of hydrological regimes showed that, for all nutrient fractions, most export occurred during stormflow. However, the proportion of nitrate flux exported as baseflow was much greater than the proportion of SRP flux exported as baseflow, for all three watersheds (25-37% of nitrate exported as baseflow vs. 3-13% of SRP exported as baseflow). In addition, baseflow comprised a greater proportion of total discharge in the intermediate-sized watershed (43.7% of total discharge) than the other two watersheds (29.3 and 30.1%). Thus, higher nitrate export coefficients in the intermediate-sized watershed may have resulted from the greater contribution of baseflow in this watershed. Other factors potentially contributing to higher nitrate export coefficients in this watershed may be a thicker layer of loess soils and a lower proportion of riparian forest than the other watersheds. The among-watershed variability in SRP concentrations and export coefficients remains largely unexplained, and might represent the minimum expected variation among similar agricultural watersheds.

Relatively little is known about intraspecific variation in the use of chemical defenses by cosmetid harvestmen. In this study, we investigated sexual and ontogenetic variation in the emission of secretions from the scent glands and the morphology of the ozopores of Erginulus clavotibialis, a Neotropical species from Belize. Most individuals (> 94%) did not secrete when seized by leg IV, however, when the body was subsequently grasped firmly with forceps, 76% of the harvestmen (n = 96) responded by releasing enteric fluid (clear, no odor) or secretions from the scent glands (reddish-brown, distinct odor), most commonly in the form of globules near the ozopores. Adults and penultimate nymphs rarely (less than 5% of all trials) exhibited leg dabbing, an unusual behavior generally associated with cosmetid harvestmen. Males released enteric fluid (without scent gland secretions) significantly more than females or nymphs. Nymphs emitted secretions from scent glands at a significantly greater frequency than males or females. Using SEM, we examined the ozopores and the dorsal processes of coxae I and II and found that the morphology of these structures varies between adults and nymphs but not between males and females. The openings of the ozopores of nymphs are circular and are not obscured by the dorsal posterior process of coxa I and the dorsal anterior process of coxa II. In contrast, adults have subtriangular ozopores that are difficult to observe without dissection because they are partially blocked by the dorsal processes of coxae I and II.

Relatively little is known about the natural history of the cosmetid harvestmen that inhabit the forests of Central America. The primary objective of this study was to investigate habitat use among adult Cynorta marginalis . In the field, we established 15 transects (40 m in length) and sampled them repeatedly in the morning (0830–1100 h) and evening (1800–2300 h). During 45 morning and 35 evening surveys, we captured and marked 146 males and 112 females. Only three individuals (all females) were recaptured over the course of the study, indicating that the population size at this field site was relatively large. Heavy rains significantly reduced the surface activity of adults (1.1 individuals per transect during heavy rain vs. 3.7 individuals per transect during light or no rain). Harvestmen most commonly used leaves (65% of captures) or tree trunks (31%) as perches, and rarely occupied branches or the leaf litter. Only 18 adults were observed with leg injuries, with two individuals having damage to multiple legs. Perch height was significantly lower during the evening (110.9 cm at night vs. 155.1 cm during the day). Adults were most commonly found alone (85%), however, we observed several harvestmen in male-female pairs (8%), same sex pairs (4%) and heterosexual groups (3%). Although we did not observe reproductive or aggressive behaviors in the field, we observed intraspecific interactions under laboratory conditions and found that some individuals (15%) engaged in courtship suggesting that the sharing of perches by male-female pairs may be related to reproductive activity.

Relatively little is known about the food habits of neotropical harvestmen. We used Erginulus clavotibialis (Pickard-Cambridge 1905), a locally abundant species of cosmetid harvestman in Belize, in a food choice experiment. Individuals were presented with fresh fruit (pineapple) and live invertebrate prey (termites) in an experimental chamber. This species showed a strong preference for fruit, as 72% of individuals ate it first and 67% spent the most time in the fruit-containing portion of the experimental chamber. Five E. clavotibialis (13%) consumed termites, confirming this species' ability to capture and consume live invertebrate prey. Adult males located food more quickly than nymphs. Harvestmen feeding on fruit were also significantly more active than non-feeding individuals or those preying upon termites first. Opportunistic frugivory may be important to E. clavotibialis during times when fruit is available (e.g., wet season). We hypothesize that this species exhibits a generalist diet in the field.

We examined the role of the omnivorous fish, gizzard shad (Dorosoma cepedianum), in transporting nutrients from sediments into the water column and their subsequent impacts on phytoplankton. We manipulated sediment access and fish size during two mesocosm experiments to determine how these factors could alter the effects of gizzard shad on phytoplankton. In the first experiment, gizzard shad stimulated phytoplankton only when they could feed directly on lake sediments and not when benthic feeding was prevented by a mesh netting. In the second experiment, small gizzard shad stimulated phytoplankton to a greater extent than did an equivalent biomass of large gizzard shad. In the absence of gizzard shad, zooplankton became more abundant, and phytoplankton were less P limited, compared to treatments with gizzard shad present. This suggests a shift from grazer limitation in the absence of gizzard shad to direct limitation by nutrients in the presence of gizzard shad. Gizzard shad stimulated total N and P, suggesting an important nutrient transport effect. Thus, gizzard shad impact phytoplankton through an interaction of top-down and bottom-up effects, which are facilitated by a large detrital subsidy to this system.

The genetic events involved in the aetiology of non-clear-cell renal cell carcinoma (RCC) and a proportion of clear cell RCC remain to be defined. Germline mutations of the TSC1 and TSC2 genes cause tuberous sclerosis (TSC), a multi-system hamartoma syndrome that is also associated with RCC. We assessed 17 sporadic clear cell RCCs with a previously identified VHL mutation, 15 clear-cell RCCs without an identified VHL mutation and 15 non-clear-cell RCCs for loss of heterozygosity (LOH) at chromosomes 9q34 and 16p13.3, the chromosomal locations of TSC1 and TSC2. LOH was detected in 4/9, 1/11 and 3/13 cases informative at both loci. SSCP analysis of the whole coding region of the retained allele did not reveal any cases with a detectable intragenic second somatic mutation. Furthermore, RT-PCR analysis of TSC1 and TSC2 on total RNA from 8 clear-cell RCC cell lines confirmed expression of both TSC genes. These data indicate that biallelic inactivation of TSC1 or TSC2 is not frequent in sporadic RCC and suggests that the molecular mechanisms of renal carcinogenesis in TSC are likely to be distinct.