4,548 research outputs found
A hidden cause of infertility in hypothyroid patients
Methylene tetrahydrofolate reductase (MTHFR) gene mutations could be the cause of infertility in hypothyroid patients. Hence, it is worthy to screen for MTHFR gene mutations in infertile hypothyroid females and their partners if infertility persists after optimizing thyroid function
Influence of finite volume and magnetic field effects on the QCD phase diagram
The Polyakov linear sigma model (PLSM) is used to investigate the respective
influence of a finite volume and a magnetic field on the quark-hadron phase
boundary in the plane of baryon chemical potential () vs. temperature
() of the QCD phase diagram. The calculated results indicate sizable shifts
of the quark-hadron phase boundary to lower values of
for increasing magnetic field strength, and an opposite shift to higher values
of for decreasing system volume. Such shifts could
have important implications for extraction of the thermodynamic properties of
the QCD phase diagram from heavy ion data
Distance from a fishing community explains fish abundance in a no-take zone with weak compliance
There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into ‘paper parks’ through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ) of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community
DCU-TCD@LogCLEF 2010: re-ranking document collections and query performance estimation
This paper describes the collaborative participation of Dublin City University and Trinity College Dublin in LogCLEF 2010. Two sets of experiments were conducted. First, different aspects of the TEL query logs were analysed after extracting user sessions of consecutive queries on a topic. The relation between the queries and their length (number of terms) and position (first query or further reformulations) was examined in a session with respect to query performance estimators such as query
scope, IDF-based measures, simplified query clarity score, and average inverse document collection frequency. Results of this analysis suggest that only some estimator values show a correlation with query length or position in the TEL logs (e.g. similarity score between collection and query). Second, the relation between three attributes was investigated: the user's country (detected from IP address), the query language, and the interface language. The investigation aimed to explore the influence of the three attributes on the user's collection selection. Moreover, the investigation involved assigning different weights to the three attributes in a scoring function that was used to re-rank the collections displayed to the user according to the language and country. The results of the
collection re-ranking show a significant improvement in Mean Average Precision (MAP) over the original collection ranking of TEL. The results also indicate that the query language and interface language have more in
uence than the user's country on the collections selected by the users
“Sidewalk” as a Realm of Users’ Interactions: simulating pedestrians’ densities at a commercial street in Cairo City
During the last four decades, researchers have developed many tools in order to investigate pedestrians’ behavior at sidewalks. Those tools tried to study sidewalks by investigating two main components: built environment and pedestrians’ movement. This paper presents a simulation for the pedestrians’ movement at a commercial street in Cairo, using an agent-based model. The model was designed in a way by which we could examine: pedestrians’ densities, the influence of types of uses on densities, the influence of flow-generators and destinations. In addition, we categorized the uses along the selected case of study by type of service and time spent by customer.
The method which we utilized for this work could be divided into two main phases: The first phase, included site video-based survey at different times and days, by which we could calculate flow rates at each generator point, and test the influence of uses on the density along the sidewalk. The second phase was to develop the model. In parallel, we focused on the uses’ types and how it affects controls pedestrians’ densities. Our results referred to a strong relation between use’s type and densities’ distribution along the street
Non-linear optimization for parameter estimation for flood forecasting
Floods are the response of a catchment area to
severe rainfall events. Each catchment will have
its unique response which is dependent on its own
characteristics and the temporal and spatial
distribution of the oncoming rainfall event. A non
linear optimization technique has been applied to
historical data for rainfall and river flows of the
Kakanui catchment in North Otago, New Zealand,
to estimate the parameters of a model based on
the transfer function concept. The non linear
optimization is based on Powell algorithm.
Powell algorithm has been widely used in the
literature, and it is more efficient and faster than
the Simplex method (Press et al., 1989)
Observed rainfall events at two locations in the
Kakanui catchment, along with the corresponding
observed flows of the river have been utilized to
estimate the transfer function which represents the
response of the Kakanui catchment to rainfall
events. An adjusted form of Philip’s equation for
infiltration was used to estimate the abstraction of
the rainfall event and obtain the effective rainfall
which will contribute to the river flow. Weighing
factors were assigned to each of the rainfall sites
to obtain the best fit between observed and
forecasted flows. Nine flood events were used for
the calibration process, while two events were
utilized for the validation of the derived model.
The model has 19 parameters for the transfer
function, 2 parameters for the hydrologic
abstractions model, and 2 parameters for the
weighing factors of the rainfall sites. This results
in a total of 23 parameters for the developed
model. The ratio of observed cumulative rainfall
at Clifton Falls to the corresponding rainfall at the
Dasher for historical events is not consistent, and
varies significantly from one event to another.
This indicates the high variability of the spatial
distribution of rainfall events over the Kakanui
catchment. As these rainfall events were used in
the model calibration, it was difficult to obtain the
correct transfer function without proper
accounting for the spatial distribution of rainfall over the whole watershed. However, the model,
in general, performed satisfactory, given the
difficulty in representing the spatial variability of
the rainfall events. The model was capable of
simulating the flood hydrographs of several
events which were incorporated in its calibration,
but did not perform well with others. The model
was able to simulate well the flows of a flood
event which was not included in its calibration.
Moreover, in applying the derived model for a
real case event which occurred most recently on
30 July 2007, the model was able to forecast very
closely the peak flow, but the whole flow
hydrograph was not forecasted as good
Optimization of Extracellular Keratinase Production by Aspergillus Terreus Isolated From Chicken's Litter
In this current study 45 fungal isolates were isolated from chicken's litter on Feather Agar Medium (FAM) were screened for determining the potent keratinase producing isolates. Out of these fungal isolates, twelve species and one species variety exhibited various degrees of keratinolytic activities from which A. terreus showed the highest keratinase production (12.6U/ml). The optimum temperature and initial pH for keratinase production by A. terreus were 40°C and 8, respectively. The highest keratinase production was observed for a period 25 days. The optimum ionic strength for the enzyme production was 80mM NaCl. Deprivation of K+, Fe2+, Mg2+, Ca2+ or Zn2+ from the culture medium drastically reduced the keratinase production by A. terreus. In contrast, sulfur deprivation did not significantly affect the keratinase production. The Km and Vmax values for A. terreus keratinase were 8.64mg keratin and 56.7U/mg proteins, respectively. The optimum temperature, pH and ionic strength for keratinase activity were 35°C, 7.8 and 80-100mM NaCl, respectively
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