scholarly journals Drone-based effective counting and ageing of hippopotamus (Hippopotamus amphibius) in the Okavango Delta in Botswana

2019 ◽  
Author(s):  
Victoria L. Inman ◽  
Richard T. Kingsford ◽  
Michael J. Chase ◽  
Keith E. A. Leggett

AbstractAccurately estimating hippopotamus (Hippopotamus amphibius) numbers is difficult due to their aggressive nature, amphibious lifestyle, and habit of diving and surfacing. Traditionally, hippos are counted using aerial surveys and land/boat surveys. We compared estimates of numbers of hippos in a lagoon in the Okavango Delta, counted from land and video taken from a DJI Phantom 4™ drone, testing for effectiveness at three heights (40 m, 80 m, and 120 m) and four times of day (early morning, late morning, early afternoon, and late afternoon). In addition, we determined effectiveness for differentiating age classes (juvenile, subadult, and adult), based on visual assessment and measurements from drone images, at different times and heights. Estimates in the pool averaged 9.18 (± 0.25SE, range 1 – 14, n = 112 counts). Drone counts at 40 m produced the highest counts of hippos, 10.6% higher than land counts and drone counts at 80 m, and 17.6% higher than drone counts at 120 m. Fewer hippos were counted in the early morning, when the hippos were active and most likely submerged, compared to all other times of day, when they tended to rest in shallow water with their bodies exposed. We were able to assign age classes to similar numbers of hippos from land counts and counts at 40 m, although land counts were better at identifying juveniles and subadults. Early morning was the least effective time to age hippos given their active behaviour, increasingly problematic with increasing height. Use of a relatively low-cost drone provided a rigorous and repeatable method for estimating numbers and ages of hippos, but not in the early morning.

1980 ◽  
Vol 70 (4) ◽  
pp. 549-555 ◽  
Author(s):  
J. D. Charlwood ◽  
J. Lopes

AbstractThe physiological age of female Stomoxys calcitrans (L.) caught biting horses during seven all-day catches and 20 catches in the morning or afternoon during the rainy season (January-July) in Manaus, Amazonas, Brazil, was determined by examination of their ovaries. Males and unmated females with undeveloped ovaries had similar biting patterns, with peaks of activity in the early morning and late afternoon, when the relative humidity was between 50 and 80%. Nulliparous inseminated females with ovaries at Stages II to V attacked throughout the day, with no pronounced peaks, whereas parous females showed a peak of biting in the late morning and early afternoon. The majority of parous flies had oviposited less than four times and had distended overiolar sacs, indicative of recent oviposition.


2016 ◽  
Vol 13 (7) ◽  
pp. 740-746 ◽  
Author(s):  
Lucas J. Carr ◽  
Shira Dunsinger ◽  
Bess H. Marcus

Background:Long-term physical activity surveillance has not been conducted among Latinas. This study explored the variability of daily physical activity habits of inactive adult Latinas participating in a 12-month physical activity intervention.Methods:We collected objective physical activity data (pedometer) from 139 Spanish speaking Latinas (age = 41.6 ± 10.1 years; BMI = 29.6 ± 4.3 kg/m2) enrolled in a 12-month physical activity intervention. Total and aerobic steps (>100 steps/minute) were computed by year, season, month, day of week, time of day, and hour.Results:Participants walked an average of 6509 steps/day of which 1303 (20%) were aerobic steps. Significant physical activity differences were observed for subgroups including generational status, education, employment, income, marital status and health literacy. Significant and similar differences were observed for both total steps and aerobic steps for day of the week (weekdays > weekends) and season (summer > spring > fall > winter). Opposing trends were observed over the course of the day for total steps (early afternoon > late morning > late afternoon > early morning > evening) and aerobic steps (early morning > evening > late morning > late afternoon > early afternoon).Conclusions:Both seasonality and week day predicted physical activity habits of Latinas. This is the first long-term study to track daily physical activity habits of Latinas. These data have potential to inform the design of future physical activity interventions targeting Latinas.


2019 ◽  
Vol 129 (2) ◽  
pp. 110-114
Author(s):  
Sapideh Gilani ◽  
Neil Bhattacharyya

Objective: To determine the association between intraday timing of outpatient pediatric tonsillectomy and revisit outcomes and complications. Study Design: Cross-sectional analysis of New York databases. Setting: Ambulatory surgery, emergency department and inpatient hospital settings. Subjects and Methods: The State Ambulatory Surgery, State Emergency Department and State Inpatient Databases for 2010-2011 were analyzed for revisits. Outcomes assessed were revisits for any reason, bleeding, acute pain or fever, nausea, vomiting and dehydration. The relationships between the hour of admission for surgery, the hour of discharge and the revisit outcomes were analyzed. Results: The study included 33,611 children (mean age, 6.62 years; 45.7% female) and 62.0% were admitted in the early morning. Discharges were most common in the early afternoon (28.3%). Revisit rates were significantly higher for the early evening discharges (6.0%) versus late morning discharges (3.1%) ( P < .001). Revisits for bleeding were 1.8% for discharge in the early evening versus 0.6% in the late morning ( P < .001). Revisits for fever, nausea, vomiting or dehydration were 1.8% for discharge in the early evening versus 0.9% in the late morning ( P = .002). Late afternoon admission was significantly associated with higher revisit rates (10.9%, P < .001). Bleeding revisits were highest for late afternoon admit hour (1.5%, P = .001). Revisits for acute pain were also highest for late afternoon admit hour (2.3%, P = .005). Conclusion: Revisit are significantly higher when the patient is discharged late. Late afternoon surgery is also significantly associated with higher revisit rates. Surgeons may wish to consider these findings when a late tonsillectomy or late discharge is anticipated post-tonsillectomy.


2020 ◽  
Vol 12 (23) ◽  
pp. 10089
Author(s):  
Andre M. Eanes ◽  
Todd R. Lookingbill ◽  
Jeremy S. Hoffman ◽  
Kelly C. Saverino ◽  
Stephen S. Fong

Air pollution and the urban heat island effect are consistently linked to numerous respiratory and heat-related illnesses. Additionally, these stressors disproportionately impact low-income and historically marginalized communities due to their proximity to emissions sources, lack of access to green space, and exposure to other adverse environmental conditions. Here, we use relatively low-cost stationary sensors to analyze PM2.5 and temperature data throughout the city of Richmond, Virginia, on the ten hottest days of 2019. For both hourly means within the ten hottest days of 2019 and daily means for the entire record for the year, the temperature was found to exhibit a positive correlation with PM2.5. Analysis of hourly means on the ten hottest days yielded a diurnal pattern in which PM2.5 levels peaked in the early morning and reached their minima in the mid-afternoon. Spatially, sites exhibiting higher temperatures consistently had higher PM2.5 readings, with vulnerable communities in the east end and more intensely developed parts of the city experiencing significantly higher temperatures and PM2.5 concentrations than the suburban neighborhoods in the west end. These findings suggest an uneven distribution of air pollution in Richmond during extreme heat events that are similar in pattern but less pronounced than the temperature differences during these events, although further investigation is required to verify the extent of this relationship. As other studies have found both of these environmental stressors to correlate with the distribution of green space and other land-use factors in cities, innovative and sustainable planning decisions are crucial to the mitigation of these issues of inequity going forward.


2005 ◽  
Vol 65 (2) ◽  
pp. 211-215 ◽  
Author(s):  
R. M. Bonaldo ◽  
J. P. Krajewski ◽  
I. Sazima

The banded butterflyfish (Chaetodon striatus) from the tropical and subtropical western Atlantic is a territorial, diurnal forager on benthic invertebrates. It is usually seen moving singly or in pairs, a few meters above the sea floor. We studied the foraging activity of C. striatus on rocky reefs in southeastern Brazil. This fish spent about 11 h and 30 min per day on feeding activities, and preferred colonies of non-scleratinian anthozoans over sandy and rocky substrata while foraging. The lowest feeding rates were recorded in the early morning and late afternoon, but we found no further differences between feeding rates throughout the day. We also found no differences between the feeding rates of paired and single individuals.


2008 ◽  
Vol 21 (22) ◽  
pp. 6036-6043 ◽  
Author(s):  
Jian Li ◽  
Rucong Yu ◽  
Tianjun Zhou

Abstract Hourly station rain gauge data are employed to study the seasonal variation of the diurnal cycle of rainfall in southern contiguous China. The results show a robust seasonal variation of the rainfall diurnal cycle, which is dependent both on region and duration. Difference in the diurnal cycle of rainfall is found in the following two neighboring regions: southwestern China (region A) and southeastern contiguous China (region B). The diurnal cycle of annual mean precipitation in region A tends to reach the maximum in either midnight or early morning, while precipitation in region B has a late-afternoon peak. In contrast with the weak seasonal variation of the diurnal phases of precipitation in region A, the rainfall peak in region B shifts sharply from late afternoon in warm seasons to early morning in cold seasons. Rainfall events in south China are classified into short- (1–3 h) and long-duration (more than 6 h) events. Short-duration precipitation in both regions reaches the maximum in late afternoon in warm seasons and peaks in either midnight or early morning in cold seasons, but the late-afternoon peak in region B exists during February–October, while that in region A only exists during May–September. More distinct differences between regions A and B are found in the long-duration rainfall events. The long-duration events in region A show dominant midnight or early morning peaks in all seasons. But in region B, the late-afternoon peak exists during July–September. Possible reasons for the difference in the diurnal cycle of rainfall between the two regions are discussed. The different cloud radiative forcing over regions A and B might contribute to this difference.


2014 ◽  
Vol 10 (1) ◽  
pp. 39-47
Author(s):  
B.E. Bergstrom ◽  
J.H. Foreman ◽  
C.R. Foreman ◽  
A.M. Barger

Sodium bicarbonate and other alkalinising solutions (‘milkshakes’) have been given to horses surreptitiously before exercise to provide exogenous buffering effects. After an initial positive blood test, some accused horse trainers claim that their horses ‘naturally test high’, so some jurisdictions allow a secured quarantine in which the horse is tested multiple times. The objective of this experiment was to determine the intra- and inter-day variability of plasma total CO2 (tCO2) and other plasma strong ions in a group of sedentary horses housed similarly to a quarantine period. The hypothesis was that plasma tCO2 would not remain constant over a multi-day monitoring interval, but would vary measurably during that interval. Eight sedentary (unconditioned) horses were studied for 2 weeks. Horses were acclimated to a climate-controlled indoor environment and an alfalfa-only diet for a minimum of 10 days prior to sampling. Horses were sampled 3 times daily for 5 consecutive days at 7:00, 11:00 and 15:00 h. Blood samples were collected directly into 10 ml heparinised evacuated glass tubes by jugular venipuncture using a double-ended 0.91 mm needle. Samples were chilled until concentrations of plasma tCO2, Na+, K+, and Cl-, were determined within 1-3 h of sampling using an automated serum chemistry analyzer which was calibrated daily using commercial reagents obtained from the manufacturer as well as externally-obtained NIST-traceable calibrating solutions. Mean results documented mild variations in mean plasma tCO2 (range 28.9-31.6 mmol/l), but individual horses’ plasma tCO2 ranged over 4-7 units. Results showed that there was considerable intra- and inter-individual variability in plasma tCO2. Mean pooled tCO2 and measured strong ion difference (SIDm) differed by time-of-day, with both late morning and early afternoon values lower than early morning values (P<0.001). There was a strong positive linear relationship between plasma SIDm and tCO2 (r=0.75, P<0.001).


2001 ◽  
Vol 61 (2) ◽  
pp. 287-294 ◽  
Author(s):  
F. H. HATANO ◽  
D. VRCIBRADIC ◽  
C. A. B. GALDINO ◽  
M. CUNHA-BARROS ◽  
C. F. D. ROCHA ◽  
...  

We analyzed the thermal ecology and activity patterns of the lizard community from the Restinga of Jurubatiba, Rio de Janeiro, Brazil. The broadest activity was that of Tropidurus torquatus, a sit-and-wait forager, while the active foraging teiid Cnemidophorus littoralis had the shortest activity. The nocturnal gekkonid Hemidactylus mabouia was found active during the day only during early morning and late afternoon, when environmental temperatures are low. Body temperature was highest for Cnemidophorus littoralis and lowest for the two Mabuya species. The patterns found here are discussed and compared to those of congeneric species in other habitats in Brazil.


1996 ◽  
Vol 271 (6) ◽  
pp. E1092-E1097 ◽  
Author(s):  
M. Bergo ◽  
G. Olivecrona ◽  
T. Olivecrona

The activity of lipoprotein lipase (LPL) in adipose tissue is modulated by changes in the nutritional status. We have measured LPL activity, mass, and mRNA levels in rat adipose tissue during normal feeding cycles, during short- and long-term fasting, and during refeeding after fasting. LPL activity displayed a diurnal rhythm. The activity was highest during the night and early morning, decreased to a minimum during the early afternoon, and then increased again. These changes corresponded to the feeding pattern. The increases and/or decreases resulted from changes in LPL synthetic rate compounded by posttranslational mechanisms. During short-term fasting, LPL specific activity decreased to < 30% of control. The specific activity was restored within 4 h by refeeding. On longer fasting, LPL mRNA decreased. This became significant from 36 h. On refeeding, it took 12 h to restore the mRNA levels, whereas tissue LPL activity and mass could not be fully restored by 36 h of refeeding. These data show that LPL activity during short-term fasting is regulated posttranscriptionally, which allows for quick upregulation after refeeding. On longer fasting, other mechanisms affecting LPL transcription and synthesis come into play, and upregulation after refeeding is slowed down.


2011 ◽  
Vol 29 (10) ◽  
pp. 1783-1792 ◽  
Author(s):  
A. Viljanen ◽  
E. Tanskanen

Abstract. We investigate the characteristics of rapid geomagnetic variations at high latitudes based on the occurrence of large time derivatives of the horizontal magnetic field (dH/dt exceeding 1 nT s−1). Analysis of IMAGE magnetometer data from North Europe in 1983–2010, covering more than two solar cycles, confirms and specifies several previous findings. We show that dH/dt activity is high around the midnight and early morning hours, and nearly vanishes at noon and early afternoon. This happens during all seasons, although the midnight maximum is nearly invisible during summer. As indicated by modelled ionospheric equivalent currents, large dH/dt values occur predominantly during westward ionospheric electrojets. Before and around midnight, dH/dt tends to be north-south oriented, whereas in the morning hours, its direction is more west-east directed. dH/dt tends to be more strictly north-south oriented during winter than other seasons. The seasonal occurrence of large dH/dt values is similar to the variation of the maximum amplitude of westward equivalent currents. The yearly fraction of east-west directed large dH/dt vectors at the Kilpisjärvi station (MLAT 65.88) varies from 31 to 47 % without any clear correlation with the general geomagnetic activity nor with the yearly averages of solar wind parameters.


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