A PRELIMINARY INVESTIGATION OF THE FACTORS REGULATING POPULATION SIZE IN THE WOODPIGEON COLUMBA PALUMBUS

We used data from Christmas Bird Counts (1961-1984) and road counts (1983-1985) to study the winter population ecology of Snowy Owls (Nyctea scandiaca) on the Great Plains of North America. Numbers of owls wintering between 45°N and 53°N increased with latitude. Owl abundance fluctuated from year to year, but fluctuations were not synchronous among count localities across the Great Plains. Owls first appeared on our study sites in southwestern Alberta in early November and individuals continued to arrive until late December or early January. Spring departure occurred during late February and early March, with a few owls remaining until late March. During midwinter, the mean number of owls censused on four study sites ranged from 1.3 to 5.8 owls/100 km in 1983-1984 and from 1.7 to 10.2 owls/100 km in 1984-1985. Although all age-sex classes were represented on the Alberta study areas in both winters, adult birds predominated. Both the Christmas Bird Count data and our fieldwork indicate that owl dispersion is patchy, and that the abundance of owls within patches may vary markedly from year to year. We recommend that future studies of winter raptor populations select multiple study sites to permit detection of patterns that occur over areas larger than a single study site.

Productivity and profitability of cotton–wheat system as influenced by relay intercropping of insect resistant transgenic cotton in bed planted wheat

\Veights of 1,281 diving ducks of five species livetrapped on Seneca Lake, Ontario County New Tork, during January, February, and March of 1960, 1961, 1962, 196S, and 1971 are reported. Body weights drop significantly from early January through late February and March. The weight loss by redheads (Aythya americana) is emphasized with significant differences shown in the ll-year time span between 19160 and 1971. To make conjectures as to this difference, it is suggested that periods of zero to subzero temperatures occurring in 1971 and not in 1960 influenced weight loss. Also, dramatically different, and possibly less suitable, food resources dominating the aquatic environment of the lake in 1971 contributed to weight loss. After a flurry of attention given to publishing records of the body weights of birds in the 1920's and 1930's, little new information appeared. With some notable exceptions, waterfowl, largely neglected during the early period, have continued to be neglected. Leopold (1919) recorded weights of a number of species shot during the gunning seasons of 1917 and 1918 in the Rio Grande Valley near Albuquerque, New Mexico, and offered some generalizations regarding weight changes during fall and winter. Kortright ( 1942 ) serves with Bent ( 1923 ) as a good starting point for many aspects of the life histories of waterfowl. However, Bent offers little or nothing on body weight, and Kortright's data, although based on sizable numbers of individuals and divided on the basis of sex, do not indicate the time of year when the records were made nor any distinctions relative to age. Both of these are factors of significance. Dzubin (1959) recorded the weights of both adult and young canvasbacks (Aythya valisneria ) in Manitoba. Weller's ( 1957 ) work with redheads, most of it done at Delta \07aterfowl Research Station in south1 This is a contribution of the Federal Aid to Wildlife Restoration Program, New York PittmanRobertson Project W-39-R. ern Manitoba) offers good records of the body weights of this species. His data included weights of both sexes, adults and immatures, and spring, summer, and fall records. He also included weights of redheads from Utah and Michigan. Bellrose and Hawkins ( 1947 ) tabulated the average weights of ducks shot in the Illinois River Valley from 1938 through 1940 and included the weights of small numbers of redheads and canvasbacks and good samples of lesser scaup (Aythya affinis). Weights were categorized by age and sex. Longcore and Cornwell (1964) gave the weights of captive, immature canvasbacks and lesser scaups in conjunction with their study of the consumption of natural foods by these two species. In August 1962, near Fort Yukon, Alaska, approximately 10,000 flightless ducks were driven into a large trap on Ohtig Lake. One objective was to weigh large numbers of diving ducks. Yocom (1970) reported this remarkable effort and gave the weights of 355 adult diving ducks of seven species. The object of the present paper is to place on record the body weights of over 1,200 individual diving ducks of five species recorded during the winter period of January, February, and early March, and, in a number of cases, in late March. In 1960. weights were recorded as late as mid-April.

Nymph and adult populations of Diclidophlebia eastopi Vondráček and D. harrisoni Osisanya were counted weekly on 3- or 4-year-old trees, Triplochiton scleroxylon, in Nigeria during 1966–71. D. eastopi showed successively larger peaks in late January or early February, mid-August, and early or mid-September; the smallest populations were in mid or late March. D. harrisoni showed peaks in February, late July or early August, and late October or early November, the second peak being the largest. Multiple regression analysis of Diclidophlebia populations against rainfall, saturation deficit, temperature and time showed that temperature had the greatest, although slight, effect on D. eastopi, while saturation deficit, through the host-plant, had a marked effect on D. harrisoni. D. harrisoni populations were dependent on the availability of young leaves. It is concluded that, to avoid attack by Diclidophlebia, transplanting of Triplochiton seedlings should be in late February or early March.

Abstract. We present a detailed discussion of the chemical and dynamical processes in the Arctic winters 1996/1997 and 2010/2011 with high resolution chemical transport model (CTM) simulations and space-based observations. In the Arctic winter 2010/2011, the lower stratospheric minimum temperatures were below 195 K for a record period of time, from December to mid-April, and a strong and stable vortex was present during that period. Simulations with the Mimosa-Chim CTM show that the chemical ozone loss started in early January and progressed slowly to 1 ppmv (parts per million by volume) by late February. The loss intensified by early March and reached a record maximum of ~2.4 ppmv in the late March–early April period over a broad altitude range of 450–550 K. This coincides with elevated ozone loss rates of 2–4 ppbv sh−1 (parts per billion by volume/sunlit hour) and a contribution of about 30–55% and 30–35% from the ClO-ClO and ClO-BrO cycles, respectively, in late February and March. In addition, a contribution of 30–50% from the HOx cycle is also estimated in April. We also estimate a loss of about 0.7–1.2 ppmv contributed (75%) by the NOx cycle at 550–700 K. The ozone loss estimated in the partial column range of 350–550 K exhibits a record value of ~148 DU (Dobson Unit). This is the largest ozone loss ever estimated in the Arctic and is consistent with the remarkable chlorine activation and strong denitrification (40–50%) during the winter, as the modeled ClO shows ~1.8 ppbv in early January and ~1 ppbv in March at 450–550 K. These model results are in excellent agreement with those found from the Aura Microwave Limb Sounder observations. Our analyses also show that the ozone loss in 2010/2011 is close to that found in some Antarctic winters, for the first time in the observed history. Though the winter 1996/1997 was also very cold in March–April, the temperatures were higher in December–February, and, therefore, chlorine activation was moderate and ozone loss was average with about 1.2 ppmv at 475–550 K or 42 DU at 350–550 K, as diagnosed from the model simulations and measurements.

The <scp>UK</scp>’s wet and stormy winter of 2013/2014

Polar stratospheric clouds (PSCs) play a key role in Arctic amplification and stratospheric ozone destruction in polar regions. In this paper, we used the CALIPSO data to analyze the spatiotemporal distribution of Arctic PSCs from 2006 to 2021. We found that Arctic PSCs mainly appear in December, peak in late December and early January, disappearing in late February and early March. PSCs can extend from heights near the tropopause to over 25 km. However, there is the lowest fraction of PSCs in the 2014/2015 winter. This study found that the temperature in the 2014/2015 winter was warmer than the 15‐year average temperature, with the lowest temperature slightly below the PSCs formation temperature of about 5 K. The formation of the Ural blocking high accompanied by the poleward propagation of the planetary wave caused a sudden stratospheric warming (SSW) event on 3 January 2015, during which the warm air entered the polar vortex and divided it into two lobes. Additionally, a reduction in SO2 column mass density before the SSW event resulted PSCs occurring with a frequency of only 0.148 and dissipating rapidly in December. Moreover, the concentration of H2O and HNO3 in the gravitational settling process of PSCs decreased by 20–50%, the reduction of condensation nuclei made PSCs with the highest frequency of 0.074 in February appear briefly and then disappear. The chemical and dynamic analysis of PSCs formation is needed to further understand the spatiotemporal distribution of Arctic PSCs and to better predict future Arctic amplification and ozone destruction.

Absolute density sampling was conducted to determine population densities of Hypera postica (Gyllenhal) eggs and larvae at two locations in central Oklahoma from 1971 to 1990. For each generation of the weevil, egg deposition began following the return of adults from summer estivation sites during October and November and continued until the following April. Although hatching began as early as December, the appearance of large numbers of larvae coincided with growth of the first alfalfa crop from February to May. Depending upon effects of weather conditions on egg development and survival, the time when larval numbers first exceeded the economic threshold ranged from late February to April. Multivariate discriminant analysis with five variables related to weevil egg numbers and temperature conditions was used in deriving a model for predicting by 15 February whether the economic threshold would be exceeded in late February, early March (1–15), late March (16–31), or April. When tested, >90% of the predictions of the model were correct. This model will provide valuable assistance to growers and consultants in determining when field scouting should be conducted to make decisions regarding sprays for alfalfa weevil control.

Seasonal movements and distribution of primiparous and multiparous red king crabs (Paralithodes camtschaticus) were monitored with ultrasonic biotelemetry approximately weekly for 1 year in Auke Bay, Alaska. Migration was associated with life-history events and may have occurred in response to spatial and temporal variations in environmental conditions and resources. All crabs displayed distinct shifts in depth and habitat use and followed a general pattern of seasonal movement as follows: (1) gradual movement to deep water in spring after mating and egg extrusion, and residence there through early November; (2) abrupt, synchronous movement into shallow-water areas in November, and residence there through late February or early March; and (3) gradual, synchronous movement to intermediate depths followed by movement into shallow water to molt and mate between late March and late May. The behavior of primiparous crabs was more variable than that of multiparous crabs. The differences in behavior may result from ontogenetic shifts in movements, and habitat selection. The annual range of primiparous crabs (x = 11.9 km2) exceeded that of multiparous crabs x( = 3.6 km2). Mean depth was directly correlated with photoperiod, and the sudden, synchronous movement of crabs between habitats coincided with thermohaline mixing. Females displayed a highly aggregated distribution, especially during winter in shallow water, where podding behavior of adult crabs was documented for the first time.

Seasonal movements and distribution of primiparous and multiparous red king crabs (Paralithodes camtschaticus) were monitored with ultrasonic biotelemetry approximately weekly for 1 year in Auke Bay, Alaska. Migration was associated with life-history events and may have occurred in response to spatial and temporal variations in environmental conditions and resources. All crabs displayed distinct shifts in depth and habitat use and followed a general pattern of seasonal movement as follows: (1) gradual movement to deep water in spring after mating and egg extrusion, and residence there through early November; (2) abrupt, synchronous movement into shallow-water areas in November, and residence there through late February or early March; and (3) gradual, synchronous movement to intermediate depths followed by movement into shallow water to molt and mate between late March and late May. The behavior of primiparous crabs was more variable than that of multiparous crabs. The differences in behavior may result from ontogenetic shifts in movements, and habitat selection. The annual range of primiparous crabs (x = 11.9 km2) exceeded that of multiparous crabs x( = 3.6 km2). Mean depth was directly correlated with photoperiod, and the sudden, synchronous movement of crabs between habitats coincided with thermohaline mixing. Females displayed a highly aggregated distribution, especially during winter in shallow water, where podding behavior of adult crabs was documented for the first time.

"Wisdom comes to us when it can no longer do any good". Gabriel García Márquez, in Love in the Time of Cholera Respiratory Disease, Respiratory Failure, and Ventilator Shortages Those were the concerns in late February and early March, shortly before the surge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) hit the United States. By late March, not only were intensive care unit beds full and respiratory failure rampant in some major cities in the United States, but there was a new enemy lurking. The tsunami started to hit. It was not volume depletion-induced serum creatinine elevations. It was severe AKI with multiple electrolyte derangements. Troops were summoned and dialysis nurses worked around the clock to try to provide clearance to patients all over hospitals. Four-hour dialysis treatments were a thing of the past; 2 hours sometimes had to suffice. While President Trump enacted the Defense Production Act to force companies to make more ventilators, kidneys and life-sustaining dialysis machines were the forgotten resources. How did this happen? By the beginning of June, over 6.9 million patients had been diagnosed worldwide and more than 400,000 people had died. However, the early reports from China noted a relatively low incidence of AKI, some as low as 0.5%, with most studies reporting cumulative incidence in the single digits to the teens (1). Thus, the United States was not expecting an onslaught with regard to kidney disease Now that the initial wave of the pandemic has passed, five studies from centers in the United States have come out documenting a much higher proportion (19%–43%) of AKI in hospitalized patients with COVID-19 (Table 1). Table 1. - Reported incidence of AKI and need for RRT in United States centers Centera Paper Study Population n and Proportion with AKIb Need for RRT Northwell Health System Hirsch et al. (8) New York hospitalized (N=5449) 1993 (37%) 285 (5%) Mount Sinai Health System Chan et al. (9) New York hospitalized (N=3235) 1406 (43%) 280 (20%) Columbia Cummings et al. (5) New York critically ill (N=257) NR 79 (31%) Argenziano et al. (10) New York hospitalized (N=1000) 288 (33%) 117 (13.8%) Oschner Health Mohamed et al. (2) New Orleans hospitalized (N=575) 161 (28%) 89 (15%) NR, not recorded.aStudies of 100 patients or more.bCreatinine rise ≥0.3 mg/dl or 50% rise from baseline. One of the United States-based studies documented experiences with AKI of hospitalized patients with COVID-19 at the Ochsner Health System in New Orleans (2). The overall incidence of AKI in this cohort was 28%, which aligns with the other United States-based reports (Table 1). Over one half of patients with AKI required acute dialysis; 98% of these patients received sustained low efficiency dialysis, and only two patients never required prolonged intermittent renal replacement therapy or continuous renal replacement therapy. These findings highlight how truly sick patients with COVID-19 were. Unique features of this study from Mohamed et al. are that the majority (71%) of the cohort were black and the authors performed manual chart reviews in an effort to ascertain the causes of AKI. As we and likely others have seen, many patients with severe AKI eventually made comfort care or died before RRT initiation. Whereas most papers consider this as "never having received dialysis," in their paper Mohamed et al. classified these patients as "patients who died with a rising serum creatinine and oliguria" and chose to treat them as if they had required RRT. This subpopulation accounted for 21.6% of the total number of RRT patients. This unique characterization likely reduces information bias (informative censoring of the outcome of interest due to the competing risk of death or comfort care), and should be considered when comparing the incidence of severe dialysis-requiring AKI with other studies on AKI and COVID-19. The authors should also be commended on their manual chart review of medical records and notes of >600 patients to identify the causes of AKI. Through their chart review, the authors found that 66% of patients had acute tubular injury. Urinalysis revealed a large proportion of patients with 2+ proteinuria overall (69%) of which 39% were found to be de novo proteinuria. Moreover, 69% had hematuria of which 19% was 2+ or ≥8 red blood cells/hpf. Unfortunately, this study did not report urinalysis findings in patients without AKI. A small portion of the cohort had urinary sediment microscopy performed; additional details of the urine sediment were published in a separate paper (3). The second study from the Oschner investigators is, to date, the only study in the United States to have reported urine sediment in patients with COVID-19 and AKI. Hopefully, as the potential risks of SARS-CoV-2 infectivity in urine become better understood, more urinary sediment evaluation will be performed and reported, given its diagnostic value. Three patients underwent percutaneous kidney biopsy, of which all had collapsing glomerulopathy. This histopathologic finding has been reported in several case reports of patients with COVID-19 and AKI. Given that the majority of patients were black, it would be of interest to know the proportion of patients in this cohort that had the high-risk APOL-1 genotype, given the association between APOL1 and development of collapsing FSGS in patients with and without HIV. Postmortem studies of kidney tissue report detection of virus in the kidney tubular epithelium and podocytes (4). However, these patients are likely to have had the most severe cases of COVID-19 and, so far, there has been no detection of SAR-CoV-2 in kidney biopsies. Why do the studies from China have such differing incidence and outcomes of AKI compared with those in the United States? One potential reason may be related to the much higher burden of reported comorbidities in the United States cohorts compared with the Chinese cohorts (Figure 1) (1,2,5). Many of these comorbidities have been associated with worse outcomes in hospitalized patients with COVID-19. Additionally, there may be differences in angiotensin-converting enzyme 2 expression between Asians and occidental persons in various nephron segments, including the proximal tubules, which may explain the increased risk for AKI with SARS-CoV-2 in non-Asians (6). As more reports from other countries come out, it is becoming clearer that there are indeed regional differences in the incidence of AKI, with a study from France reporting that 80% of hospitalized patients developed AKI (7). Although there are nearly 2 million confirmed cases of COVID-19 in the United States alone, data regarding kidney outcomes have only emerged from limited sites thus far (Table 1). To truly understand the epidemiology of kidney disease in patients affected by COVID-19, we will need analyses across different health systems representing heterogeneous people of varied racial, ethnic, and cultural makeup, and health systems with different levels of resources and surge capacity. One such observational study, involving 60 sites across the United States, is currently underway [Study of the Treatment and Outcomes in Critically Ill Patients with COVID-19 (STOP-COVID) NCT04343898] and may shed some light on regional differences across the United States.Figure 1.: Proportion of reported comorbidities in studies from China and the United States. Adapted from Coca et al. (1) and updated with the United States studies listed in Table 1. HTN, hypertension; CHF, congestive heart faiolure; DM2, type 2 diabetes; Resp, respiratory.Although much remains to be elucidated about the novel SARS-CoV-2, we need to take a step back to review how much has been achieved in a very short period of time. During the early 1980s, the United States was hit by the AIDS epidemic. It took 2 years to identify the virus, and the first reports of HIV-associated nephropathy were 3 years into the epidemic. The World Health Organization was first notified of COVID-19 on December 31, 2019. The full genetic sequence of SARS-CoV-2 was publicly shared by China on January 12, 2020. Within a 6-month time span we have had numerous epidemiologic studies, several ongoing therapeutic clinical trials, and clinical trials have already begun for potential vaccines. The speed at which these things are being achieved for SARS-CoV-2 is a testament to the progress that science has made in the past few decades. Now that the surge has quieted in many segments of the United States, the next few months will a critical time in which to expand the investigations into COVID-19 and the kidneys. As the country sets to reopen the economy despite a lack of widespread immunity, and with an effective vaccine months away, it is likely only a matter of months before wave 2. Thus, we disagree with Gabriel García Márquez that "wisdom comes to us when it can no longer do any good." We have the opportunity to apply insights gained from the first wave to help us manage and triage patients with COVID-19 during the next wave, or a continued plateau that may last for several months. Some critical questions to answer include the following: (1) What is the incidence of AKI and dialysis during nonsurge conditions in patients admitted with COVID-19? (2) What is the risk of AKI to CKD transition after COVID-19 (i.e., what proportion of patients will develop incident or progressive CKD after initial hospitalization with AKI)? (3) Due to the high incidence of acute tubular injury in patients without clinical AKI (4), what will be the risk for CKD in COVID-19 survivors that experienced "subclinical AKI?" (4) What are the early predictors of both acute and severe AKI, and what are the predictors of nonrecovery and long-term CKD in patients with COVID-19? (5) What management strategies can be implemented to decrease the risk of both acute and chronic kidney outcomes? (6) What proportion of patients will have long-lasting proteinuric kidney disease, by involvement of SARS-CoV-2 in podocytes or through "second-hits" in patients with an underlying APOL1 genotype? Clinical investigators can take this summer reprieve and build up the infrastructure and data pipelines to try to inform the nephrology community, and the population at large, about the full landscape of COVID-19 kidney disease. We owe it to humanity to be better prepared against this devastating viral pandemic. Disclosures S. Coca is a cofounder and member of the advisory board of RenalytixAI and owns equity in the same. In the past 3 years, he has received consulting fees from RenalytixAI, CHF Solutions, Quark Biopharma, Takeda Pharmaceuticals, Relypsa, Bayer, Boehringer-Ingelheim, and pulseData. All remaining authors have nothing to disclose. Funding None.

Population fluctuation of some insect pests infesting sugar beet and the associated predatory insects at Kafr El-Sheikh Governorate

Out-of-season onion production is used to produce onions for the early market (April to September) when onion prices peak. No information with regard to this production method is available for the Eastern Cape. Field experiments were therefore conducted in Adelaide, Cradock and Middelburg (situated in the Fish River catchment, Eastern Cape, South Africa) to determine its viability in this area. The short-day onion cultivar ‘Z516’ was established with sets (bulbs 10–12 mm diameter) and seed on five planting dates (late January, mid February, late February, mid March and late March) in a randomised block with four replications. Marketable and unmarketable yields were recorded and percentage marketable yield of total yield calculated. Results indicated that seed is not suitable for out-of-season onion production. Sets produced the highest marketable yields and marketable yield percentage when planted in Adelaide in late February (39.68 t ha−1 [93%]), mid-March (62.60 t ha−1 [92%]) and late March (50.40 t ha−1 [89%]) and matured from April to September when onion prices peak. Cradock is marginal and Middelburg is unsuitable for out-of-season onion production because of low winter temperatures, especially from May to September.

Pruning to control tree size, flowering and production of litchi

Differential hormonal responses of Atlantic salmon parr and smolt to increased daylength: A possible developmental basis for smolting