In several butterflies, the posterior end of the hindwings resembles a butterfly head when the butterfly is perched with its wings closed. There is evidence that this "false head" (FH) deflects ...predator attacks towards non-vital parts of the body. If the FH protects from visually oriented predators, its condition in an individual butterfly could provide information about its quality to prospective mates. We tested two hypotheses based on this idea by comparing the probability of mating, duration of copulation and size of the ejaculate received by females of Callophrys xami (Lycaenidae) with an intact FH and those with an ablated FH in a paired experiment. The absence of a FH had no effect on the probability of mating, but females with an ablated FH copulated for longer and received larger ejaculates, which supports the hypothesis that males prefer females with damaged FHs because this reveals the female's ability to deflect attacks. Male or female (or both) cryptic choice could also account for our results, but more studies are needed to test this.
Stenoma impressella is one of the most important defoliator pests in oil palm plantations in Colombia. To identify an alternative method for its control was characterized biologically and molecularly ...two strains of Cordyceps cateniannulata (CPIsp1201 and IPIsp1201) and three strains of Beauveria bassiana (CPBb0502; CPBb0411; CPBb0404) against S. impressella larvae. Virulence was evaluated under laboratory conditions. In an oil palm leaflet, individual larvae obtained from the insect colony were inoculated with 5 μl of a conidial suspension containing 1 × 107 conidia/ml. The five strains were pathogenic against S. impressella larvae. CPIsp1201 and IPIsp1201 strains resulted in the highest mortality and were subsequently evaluated in two bioassays using a dose of 1 × 1013 conidia/ha. In the first bioassay, performed under shaded conditions, leaves of oil palms were infested with 75 larvae from the breeding/treatment. The second bioassay was performed in the field using natural populations. No differences were found between strains in both bioassays and the different dosages (5 × 1012, 1 × 1013, and 1.5 × 1013 conidia/ha). Finally, the two strains were evaluated under oil palm plantation conditions at a dose of 1 × 1013 conidia/ha in 126 naturally infested palms. Larval mortality caused by the strains IPIsp1201 and CPIsp1201 (79.5% and 70.5%, respectively) was higher than the natural mortality registered in the control (37.3%). Cordyceps cateniannulata used at 1 × 1013 conidia/ha was effective at controlling S. impressella.
Introduction: Hyperkalemia is a prevalent electrolyte disorder related to elevated serum potassium levels, resulting in diverse abnormal electrocardiographic findings and associated clinical signs ...and symptoms, often necessitating specific treatment. However, in some patients, these abnormal findings may not be present on the electrocardiogram even in elevated serum potassium levels. This study aims to identify electrocardiographic abnormalities related to the severity of hyperkalemia and the clinical outcomes in an emergency department in southwestern Colombia. Methodology: This is a retrospective cross-sectional descriptive study. We described the electrocardiographic findings, clinical characteristics, treatment, and outcomes related to the degrees of hyperkalemia. The potential association between the severity of hyperkalemia and electrocardiographic findings was evaluated. Results: A total of 494 patients were included. The median of the potassium level was 6.6 mEq/L. Abnormal electrocardiographic findings were reported in 61.5% of the cases. Mild and severe hyperkalemia groups reported abnormalities in 59.9% and 61.2%, respectively. The most common electrocardiography abnormalities were the peaked T wave 36.2%, followed by wide QRS 83 (16.8%). Only 1.4% of patients had adverse outcomes. The abnormal findings were registered in 61.5%. Mortality was 11.9%. The peaked T wave was the most common finding across different levels of hyperkalemia severity. Conclusion: High serum potassium levels are related with abnormal ECG. However, patients with different degrees of hyperkalemia could not describe abnormal ECG findings. In a high proportion of patients with renal chronic disease and hyperkalemia, the abnormalities in the ECG could be minimal or absent. Keywords: hyperkalemia, degree, outcomes, electrocardiographic, ECG, abnormalities
Until recently, the stem gall nematode
was only registered in eastern Colombia. However, the disease has recently been observed in central Colombian oil palm plantations that use
as a cover crop. ...Soil, root, stem, and leaf samples were collected from
. Plants showed foliar yellowing, leaf drying, and galls within stem nodes. Nematodes were identified, and the distribution, population density, and relative importance of different genera were determined. We performed morphometric and molecular identification of nematodes associated with gall symptoms. The D2-D3 segment of the large subunit-28S of ribosomal ribonucleic acid (RNA) and internal transcribed spacer (ITS) was sequenced, and phylogenetic analysis was performed.
mainly occurred in the galls and to a lesser extent in the roots and soil. Nematodes were not found in leaf or inflorescence tissue. Morphological and morphometric data confirm the presence of
in the stems of
with gall symptoms. This study is the first to report deoxyribonucleic acid (DNA) sequences of
. Based on D2-D3 and ITS partial sequences,
is a sister species of the leaf-galling nematode
(Sinm.
).
Basal stem rot (BSR), caused by
spp., is one of the most important emerging oil palm diseases in Colombia, and is restricted to two oil palm production areas in the country. To identify the causal ...agent of the disease, basidiocarp of oil palms affected by BSR were used to prepare isolates, and their pathogenicity was then assessed in pre-nursery plants. Four-month-old oil palm seedlings were inoculated with rubber wood (
) blocks colonized with dikaryotic mycelia of
. The incidence, severity, and symptoms of the pathogen were assessed. A multiregional analysis (
,
, and
) was carried out to identify the isolates; all isolates were determined to be
. Phylogenetic analyses with the three regions yielded concordant phylogenetic information and supported the distinction of the isolates with high bootstrap support. Seven isolates (CPBsZN-01-29, CPBsZN-02-30, CPBsZN-03-31, CPBsZN-04-34, CPBsZN-05-35, CPBsZN-06-36, and CPBsZN-07-38) were pathogenic in oil palm, with incidences greater than 90% and a maximum severity of 34%, and the highest severity index was found in isolates CPBsZN-03-31, CPBsZN-04-34, and CPBsZN-06-36. The pathogen was recovered from inoculated oil palms in all cases. This study reveals the pathogenic association of
with BSR in Colombia.
The use of remote sensing techniques in monitoring inland waters has become a powerful tool, considering the amount of ungauged waterbodies all over the world. The water mass balance is an essential ...subject to take into account in water management activities. The level changes of a lake surface are an indicator of the water mass balance of a basin since they reflect the water storage variations. Space borne altimeters have been successfully used in the last decade to measure lakes, rivers and wetland stages. This study presents the first analysis of Lake Izabal — the biggest lake of Guatemala (Central America) — water level fluctuations using altimetry data and
in-situ measurements. Water level variations were obtained from Envisat Radar Altimeter (RA-2) Geophysical Data Records coupled with
in-situ measurements. The analysis period included three complete years (2004 to 2006). The rainfall and temperature records over the catchment were analyzed considering that the amount of water feeding the lake, either by the tributaries and/or the groundwater, is driven by the climatic conditions over the lake's catchment. The results obtained show a good agreement between both, altimeter and
in-situ datasets (correlation coefficient: 0.83 and rms error: 0.09 m). Lake Izabal water level fluctuations have a seasonal signal forced by the rainy and dry climate seasons in the region. An abrupt lake level rise was found in July 2006 which is correlated to abnormal precipitations in June. We found a connection between the higher/lower extreme values in the lake level variations with rainfall anomalies produced by regional climate changes forced by El Niño Southern Oscillation and the Tropical North Atlantic anomaly.
Robust design optimization (RDO) is a popular framework for addressing uncertainties in the design of engineering systems by considering different statistical measures, typically the mean and ...standard deviation of the system response. RDO can lead to a wide range of different candidate designs, establishing a different compromise between these competing objectives. This work introduces a new robustness measure, termed probability of dominance, for assessing the appropriateness of each candidate design. This measure is defined as the likelihood that a particular design will outperform the rival designs within a candidate set. Furthermore, a multi-stage implementation is introduced to facilitate increased versatility/confidence in the decision-making process by considering the comparison among smaller subsets within the initial larger set of candidate designs. For enhancing the robustness in these comparisons the impact of prediction errors, introduced to address potential differences between the real (i.e. as built) system and the numerical model adopted for it, is also addressed. This extends to proper modeling of the influence of the prediction error, including selection of its probability model, as well as evaluation of its impact on the probability of dominance and on the RDO formulation itself. Two illustrative examples are presented, the first considering the design of a tuned mass damper (TMD) for vibration mitigation of harmonic excitations and the second a topology optimization problem for minimum compliance. Extensive comparisons are presented in these two examples and the discussions demonstrate the power of the proposed approach for assessing the designs’ robustness.
The water storage variations in lakes affect their physical, chemical and biological processes. Besides, the water masses of these waterbodies reflect the balance of the rainfall and evaporation with ...surface and ground waters. The lake’s water volume is estimated combining water level variations with accurate bathymetry and shore topography maps. Lake Izabal is the largest waterbody of Guatemala (approximately 673.29
km
2). Its water volume has been estimated in the past but the volume variations are still unknown. The lake water level variations are monitored in situ since 2004, but regrettably accurate information about the bathymetry and shore topography is not available. The main objective of this study was to make a first estimate of the Lake Izabal water volume variations. To do this, we combined level variations and inundated area variations. The lack of accurate bathymetry and topography maps was overcame by using inundated area variations in the assumption that every level change reflects an inundated area response, depending on bathymetry and shore topography. The level variations were estimated from an in situ moored gauged in the lake and from the ENVISAT Radar Altimeter (RA-2). The inundated area variations were obtained using 12 ENVISAT Advanced Synthetic Aperture Radar (ASAR) images. Prior to the area estimates the lake’s shoreline was extracted making use of a chain of existing image processing algorithms. The correlation analysis between in situ lake levels and inundated area variations yielded a correlation coefficient of 0.9. The volume variations of the lake were then estimated on the dates of the acquired SAR images. Then, a group of rating curves relating level, area and volume were developed. In order to extend the area and volume estimates to the whole study time period (February 2003 to December 2006) the lake levels from the RA-2 dataset were entered to the rating curves. The estimated water volume variations of Lake Izabal range between 8271.2
×
10
6
m
3 (17th December of 2005) and 9018.15
×
10
6
m
3 (15th July of 2006) in agreement with the most recent estimation of the Lake Izabal water volume (8300
×
10
6
m
3). Regarding the inundated area variations, they range between 672.44
×
10
6
m
2 (17th December of 2005) and 677.2
×
10
6
m
2 (15th July of 2006) in agreement with the Guatemalan government information (673.29
km
2). The water volume, inundated area and water level fluctuations of the Lake Izabal show a strong seasonal signal with high stages during the rainy season (May–November) and low stages during the dry seasons (December–April). These results give valuable information for the Lake Izabal management and strengthen the idea of using remote sensing as a powerful and cheap complementary tool for hydrologic purposes.
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