BACTERIAL DESEASES IN SEA FISH

Razvojem uzgoja ribe u moru povećalo se zanimanje za praćenje njihova zdravstvenoga stanja. Razlog su tome bolesti, odnosno uginuća, koja se pojavljuju u takvim ribogojilištima, te uzrokuju velike ekonomske gubitke. Smještajem velike količine ribe na malu površinu promijenjeni su prirodni uvjeti, pa je osjetljivost i podložnost ribe uzročnicima (virusima, bakterijama, parazitima) bolesti veća. Osim toga, velika gustoća riba u uzgoju pospješuje širenje bolesti, ali isto tako i njihovo bolje zamjećivanje. Kod divljih populacija oboljele jedinke brzo postanu plijen grabežljivaca, pa je i uočavanje patološkoga stanja takvih riba otežano. Danas postoji niz napisa o virusnim, bakterijskim i parazitarnim bolestima, ali je ovdje pažnja posvećena isključivo bakterijskim bolestima koje se javljaju u kontroliranom uzgoju u moru (vibrioza, furunkuloza, pastereloza, nokardioza, mikobakterioza, edvardsieloza, jersinioza, bolesti uzrokovane bakterijama roda Flexibacter, Pseudomonas, Aeromonas, Streptococcus i bakterijski nefritis). Pritom, spoznaje o njima veoma variraju, ovisno o tome uzgaja li se neka morska vrsta ribe već duže razdoblje ili se tek uvodi u kontrolirani uzgoj.With development of the fish culturing in the sea, the interest in their health also increased. The reason for this are diseases or rather mortality that occur in such controlled cultures and cause great economic losses. By growing large quantities of fish in rather small species, natural conditions are changed, so fish is more sensitive and prone to infection agents (viruses, bacteria, parasites). Besides, a large fish density in the cultural process accelerates spreading if the diseases, but also enables a better perception of them. In wild populations sick specimen very quickly become predator’s prey, witch makes it difficult to note any pathological changes in such fish. There are lots of articles on viral, bacterial and parasitic diseases nowdays, but this work deals exclusively with bacterial deseases that occur in the controlled sea cultures (vibriosis, furunculosis, pastherelosis, nocardiosis, mycobaceriosis, edwardsielosis, yersiniosis, deseases caused by bacteria of genera Flexibacter, Pseudomonas, Aeromonas, Streptococus and bacteria nephryithis). Yet, the knowledge of these deseases vary, depending on wether a fish species is being cultured for a longer period of time or is only being introduced in the controlled culture

BACTERIAL DESEASES IN SEA FISH

Razvojem uzgoja ribe u moru povećalo se zanimanje za praćenje njihova zdravstvenoga stanja. Razlog su tome bolesti, odnosno uginuća, koja se pojavljuju u takvim ribogojilištima, te uzrokuju velike ekonomske gubitke. Smještajem velike količine ribe na malu površinu promijenjeni su prirodni uvjeti, pa je osjetljivost i podložnost ribe uzročnicima (virusima, bakterijama, parazitima) bolesti veća. Osim toga, velika gustoća riba u uzgoju pospješuje širenje bolesti, ali isto tako i njihovo bolje zamjećivanje. Kod divljih populacija oboljele jedinke brzo postanu plijen grabežljivaca, pa je i uočavanje patološkoga stanja takvih riba otežano. Danas postoji niz napisa o virusnim, bakterijskim i parazitarnim bolestima, ali je ovdje pažnja posvećena isključivo bakterijskim bolestima koje se javljaju u kontroliranom uzgoju u moru (vibrioza, furunkuloza, pastereloza, nokardioza, mikobakterioza, edvardsieloza, jersinioza, bolesti uzrokovane bakterijama roda Flexibacter, Pseudomonas, Aeromonas, Streptococcus i bakterijski nefritis). Pritom, spoznaje o njima veoma variraju, ovisno o tome uzgaja li se neka morska vrsta ribe već duže razdoblje ili se tek uvodi u kontrolirani uzgoj.With development of the fish culturing in the sea, the interest in their health also increased. The reason for this are diseases or rather mortality that occur in such controlled cultures and cause great economic losses. By growing large quantities of fish in rather small species, natural conditions are changed, so fish is more sensitive and prone to infection agents (viruses, bacteria, parasites). Besides, a large fish density in the cultural process accelerates spreading if the diseases, but also enables a better perception of them. In wild populations sick specimen very quickly become predator’s prey, witch makes it difficult to note any pathological changes in such fish. There are lots of articles on viral, bacterial and parasitic diseases nowdays, but this work deals exclusively with bacterial deseases that occur in the controlled sea cultures (vibriosis, furunculosis, pastherelosis, nocardiosis, mycobaceriosis, edwardsielosis, yersiniosis, deseases caused by bacteria of genera Flexibacter, Pseudomonas, Aeromonas, Streptococus and bacteria nephryithis). Yet, the knowledge of these deseases vary, depending on wether a fish species is being cultured for a longer period of time or is only being introduced in the controlled culture

Drought assessment using local and large-scale forcing data in small catchments

Drought is a natural hazard that occurs all over the world with significant impacts. For drought analysis, long time series of hydrometeorological variables are required. In many catchments around the world, insufficient hydrometeorological observations are available. Recently, global gridded re-analysis meteorological datasets with coarse spatial resolutions (0.5º × 0.5º) became available. In this study, the potential use of a largescale dataset at catchment scale was investigated by comparison of drought characteristics. A conceptual, hydrological model was forced with local and large-scale data to simulate time series of discharge, from which hydrological droughts were identified. The study was carried out in two contrasting catchments: Narsjø (Norway) and Upper-Metuje (Czech Republic). Similar results were obtained from drought analysis using either local or large-scale data. This holds for several drought characteristics. These results are encouraging for use of large-scale forcing data for drought research in small catchments with no, or limited observation

Drought assessment using local and large-scale forcing data in small catchments

Drought is a natural hazard that occurs all over the world with significant impacts. For drought analysis, long time series of hydrometeorological variables are required. In many catchments around the world, insufficient hydrometeorological observations are available. Recently, global gridded re-analysis meteorological datasets with coarse spatial resolutions (0.5º × 0.5º) became available. In this study, the potential use of a largescale dataset at catchment scale was investigated by comparison of drought characteristics. A conceptual, hydrological model was forced with local and large-scale data to simulate time series of discharge, from which hydrological droughts were identified. The study was carried out in two contrasting catchments: Narsjø (Norway) and Upper-Metuje (Czech Republic). Similar results were obtained from drought analysis using either local or large-scale data. This holds for several drought characteristics. These results are encouraging for use of large-scale forcing data for drought research in small catchments with no, or limited observation

Flood spatial coherence, triggers, and performance in hydrological simulations : Large-sample evaluation of four streamflow-calibrated models

Floods cause extensive damage, especially if they affect large regions. Assessments of current, local, and regional flood hazards and their future changes often involve the use of hydrologic models. A reliable hydrologic model ideally reproduces both local flood characteristics and spatial aspects of flooding under current and future climate conditions. However, uncertainties in simulated floods can be considerable and yield unreliable hazard and climate change impact assessments. This study evaluates the extent to which models calibrated according to standard model calibration metrics such as the widely used Kling-Gupta efficiency are able to capture flood spatial coherence and triggering mechanisms. To highlight challenges related to flood simulations, we investigate how flood timing, magnitude, and spatial variability are represented by an ensemble of hydrological models when calibrated on streamflow using the Kling-Gupta efficiency metric, an increasingly common metric of hydrologic model performance also in flood-related studies. Specifically, we compare how four well-known models (the Sacramento Soil Moisture Accounting model, SAC; the Hydrologiska Byrans Vattenbalansavdelning model, HBV; the variable infiltration capacity model, VIC; and the mesoscale hydrologic model, mHM) represent (1) flood characteristics and their spatial patterns and (2) how they translate changes in meteorologic variables that trigger floods into changes in flood magnitudes. Our results show that both the modeling of local and spatial flood characteristics are challenging as models underestimate flood magnitude, and flood timing is not necessarily well captured. They further show that changes in precipitation and temperature are not always well translated to changes in flood flow, which makes local and regional flood hazard assessments even more difficult for future conditions. From a large sample of catchments and with multiple models, we conclude that calibration on the integrated Kling-Gupta metric alone is likely to yield models that have limited reliability in flood hazard assessments, undermining their utility for regional and future change assessments. We underscore that such assessments can be improved by developing flood-focused, multi-objective, and spatial calibration metrics, by improving flood generating process representation through model structure comparisons and by considering uncertainty in precipitation input.</p

Clinical features and surgical outcomes of intracranial and spinal cord subependymomas

Objective: Subependymomas are low-grade ependymal tumors whose clinical characteristics, radiographic features, and postsurgical outcomes are incompletely characterized due to their rarity. The authors present an institutional case series and a systematic literature review to achieve a better understanding of subependymomas. Methods: Adult patients with histologically confirmed subependymoma or mixed subependymoma-ependymoma surgically treated at a tertiary hospital between 1992 and 2020 were identified. A systematic literature review of the PubMed, Embase, Web of Science, and Google Scholar databases from inception until December 4, 2020, was conducted according to PRISMA guidelines. Data extracted from both groups included demographics, radiographic features, tumor characteristics, management, and follow-up variables. Results: Forty-eight unique patients with subependymoma were identified by chart review; of these patients, 8 (16.7%) had mixed subependymoma-ependymoma tumors. The median age at diagnosis was 49 years (IQR 19.8 years), and 26 patients (54.2%) were male. Forty-two patients (87.5%) had intracranial subependymomas, and 6 (12.5%) had spinal tumors. The most common presentation was headache (n = 20, 41.7%), although a significant number of tumors were diagnosed incidentally (n = 16, 33.3%). Among the 42 patients with intracranial tumors, 15 (35.7%) had hydrocephalus, and the most common surgical strategy was a suboccipital approach with or without C1 laminectomy (n = 26, 61.9%). Gross-total resection (GTR) was achieved in 33 cases (68.7%), and 2 patients underwent adjuvant radiotherapy. Most patients had no major postsurgical complications (n = 34, 70.8%), and only 1 (2.1%) had recurrence after GTR. Of 2036 reports initially identified in the systematic review, 39 were eligible for inclusion, comprising 477 patients. Of 462 patients for whom tumor location was reported, 406 (87.9%) were intracranial, with the lateral ventricle as the most common location (n = 214, 46.3%). Spinal subependymomas occurred in 53 patients (11.5%), with 3 cases (0.6%) in multiple locations. Similar to the case series at the authors' institution, headache was the most common presenting symptom (n = 231, 54.0%) among the 428 patients whose presentation was reported. Twenty-seven patients (6.3%) were diagnosed incidentally, and 36 cases (8.4%) were found at autopsy. Extent of resection was reported for 350 patients, and GTR was achieved in 250 (71.4%). Fifteen of 337 patients (4.5%) had recurrence or progression. Conclusions: The authors' case series and literature review demonstrate that patients with subependymoma are well managed with resection and generally have a favorable prognosis

Assimilation of Streamflow Observations

Streamflow is arguably the most important predictor in operational hydrologic forecasting and water resources management. Assimilation of streamflow observations into hydrologic models has received growing attention in recent decades as a cost-effective means to improve prediction accuracy. Whereas the methods used for streamflow data assimilation (DA) originated and were popularized in atmospheric and ocean sciences, the nature of streamflow DA is significantly different from that of atmospheric or oceanic DA. Compared to the atmospheric processes modeled in weather forecasting, the hydrologic processes for surface and groundwater flow operate over a much wider range of time scales. Also, most hydrologic systems are severely under-observed. The purpose of this chapter is to provide a review on streamflow measurements and associated uncertainty and to share the latest advances, experiences gained, and science issues and challenges in streamflow DA. Toward this end, we discuss the following aspects of streamflow observations and assimilation methods: (1) measurement methods and uncertainty of streamflow observations, (2) streamflow assimilation applications, and (3) benefits and challenges streamflow DA with regard to large-scale DA, multi-data assimilation, and dealing with timing errors