Sleeping in a society : social aspects of sleep within colonies of honey bees (Apis mellifera)

textSleep is a behavioral condition fraught with mystery. Its definition—either a suite of diagnostic behavioral characters, electrophysiological signatures, or a combination of the two—varies in the literature and lacks an over-arching purpose. In spite of these vagaries, sleep supports a large and dynamic research community studying the mechanisms, ontogeny, possible functions and, to a lesser degree, its evolution across vertebrates and in a small number of invertebrates. Sleep has been described and examined in many social organisms, including eusocial honey bees (Apis mellifera), but the role of sleep within societies has rarely been addressed in non-human animals. I investigated uniquely social aspects of sleep within honey bees by asking basic questions relating to who sleeps, when and where individuals sleep, the flexibility of sleep, and why sleep is important within colonies of insects. First, I investigated caste-dependent sleep patterns in honey bees and report that younger workers (cell cleaners and nurse bees) exhibit arrhythmic and brief sleep bouts primarily while inside comb cells, while older workers (food storers and foragers) display periodic, longer sleep bouts primarily outside of cells. Next, I mapped sleep using remote thermal sensing across colonies of honey bees after introducing newly eclosed workers to experimental colonies and following them through periods of their adult lives. Bees tended to sleep outside of cells closer to the edge of the hive than when asleep inside cells or awake, and exhibited caste-dependent thermal patterns, both temporally and spatially. Wishing to test the flexibility of sleep, I trained foragers to a feeder and made a food resource available early in the morning or late in the afternoon. The bees were forced to shift their foraging schedule, which consequently also shifted their sleep schedule. Finally, I sleep-deprived a subset of foragers within a colony by employing a magnetic “insominator” to test for changes in their signaling precision. Sleep-deprived foragers exhibited reduced precision when encoding direction information to food sources in their waggle dances. These studies reveal patterns and one possible purpose of sleep in the context of a society.Ecology, Evolution and Behavio

Implementation Workshop: High Performance Work Organizations

A report on findings from the first Lean Aircraft Initiative (LAI) Implementation Workshop held on February 5-6, 1997. The report is not a "cookbook" or a "how to" manual. Rather, it is a summary of the first phase in a learning process. It is designed to codify lessons learned, facilitate diffusion among people not at the session, and set the stage for further learning about implementation.Lean Aerospace Initiativ

E872 Crop Budgets: Nebraska – 2010

Each budget consists of five sections: 1) The heading, 2) List of representative field operations, 3) List of materials and services used, 4) Operations and interest tabulations, and 5) Overhead costs including real estate taxes and opportunity charges. The budgets are presented in a worksheet format with a \u27\u27Your Estimate\u27\u27 column for recording modifications in costs. The heading consists of the crop name, source, amount, and application method of water, operating system description, and yield goal and yield estimate. The list of representative field operations is organized in a table with columns for the names of the operations, Times or Quantity, Labor, Fuel and Lube, and power source and implement costs for both Repairs and Ownership. Times or Quantity is typically in acres with a decimal denoting where an operation is done on a fraction of acres or where it represents the probability of an operation being done. Those operations that are done multiple times, swathing the several cuttings of hay for example, show the number of times. Other units used are bushels, hundredweight, tons, and acre inches. Labor costs for each operation were calculated from machinery accomplishment rates and adjusted for additional time required for getting machinery ready, adjusting machinery, and handling fertilizer and other supplies. The estimated costs for completing these operations are multiplied times the number in the \u27\u27Times or Qty\u27\u27 column, the product of which is multiplied times the hourly wage ($12 per hour) and labor factor. Fuel costs also use machinery accomplishment rates as well as estimated fuel consumption rates to determine fuel use. This is multiplied by a lube factor and the price of energy which is$2.00 per gallon for diesel and $0.783 per kwh for electricity. Repairs and depreciation costs were estimated using functions and factors from the Agricultural Engineer\u27s Yearbook which is published by the American Society of Agricultural and Biological Engineers. It requires making assumptions about the size and age of the equipment. It was assumed that machinery chosen was fully utilized. The age used for all field machines except irrigation equipment (pivots and pipe) was five years. The age assumed for irrigation equipment was ten years. The age assumed for all power units except diesel pumping engines and a small tractor used for spraying was five years. The age assumed for the diesel pumping engines was three years and the small spraying tractor ten years. Costing functions were based on the current list price of comparable items. For self propelled items, such as combines, the power unit repair and ownership costs estimates cover the principle machine and the implement costs covers the head. Data used for calculating power units’ cost are in Table 1 and machinery operations’ costs are in Table 2. Irrigation costs were calculated using engineering performance standards and typical water application rates which will depend on the rainfall area. Power costs for irrigation refer to the pump and power unit and implement costs are for the delivery system (pipe or pivot). Depreciation and interest for the well are budgeted with land costs

E872 Crop Budgets: Nebraska – 2010

Each budget consists of five sections: 1) The heading, 2) List of representative field operations, 3) List of materials and services used, 4) Operations and interest tabulations, and 5) Overhead costs including real estate taxes and opportunity charges. The budgets are presented in a worksheet format with a \u27\u27Your Estimate\u27\u27 column for recording modifications in costs. The heading consists of the crop name, source, amount, and application method of water, operating system description, and yield goal and yield estimate. The list of representative field operations is organized in a table with columns for the names of the operations, Times or Quantity, Labor, Fuel and Lube, and power source and implement costs for both Repairs and Ownership. Times or Quantity is typically in acres with a decimal denoting where an operation is done on a fraction of acres or where it represents the probability of an operation being done. Those operations that are done multiple times, swathing the several cuttings of hay for example, show the number of times. Other units used are bushels, hundredweight, tons, and acre inches. Labor costs for each operation were calculated from machinery accomplishment rates and adjusted for additional time required for getting machinery ready, adjusting machinery, and handling fertilizer and other supplies. The estimated costs for completing these operations are multiplied times the number in the \u27\u27Times or Qty\u27\u27 column, the product of which is multiplied times the hourly wage ($12 per hour) and labor factor. Fuel costs also use machinery accomplishment rates as well as estimated fuel consumption rates to determine fuel use. This is multiplied by a lube factor and the price of energy which is$2.00 per gallon for diesel and $0.783 per kwh for electricity. Repairs and depreciation costs were estimated using functions and factors from the Agricultural Engineer\u27s Yearbook which is published by the American Society of Agricultural and Biological Engineers. It requires making assumptions about the size and age of the equipment. It was assumed that machinery chosen was fully utilized. The age used for all field machines except irrigation equipment (pivots and pipe) was five years. The age assumed for irrigation equipment was ten years. The age assumed for all power units except diesel pumping engines and a small tractor used for spraying was five years. The age assumed for the diesel pumping engines was three years and the small spraying tractor ten years. Costing functions were based on the current list price of comparable items. For self propelled items, such as combines, the power unit repair and ownership costs estimates cover the principle machine and the implement costs covers the head. Data used for calculating power units’ cost are in Table 1 and machinery operations’ costs are in Table 2. Irrigation costs were calculated using engineering performance standards and typical water application rates which will depend on the rainfall area. Power costs for irrigation refer to the pump and power unit and implement costs are for the delivery system (pipe or pivot). Depreciation and interest for the well are budgeted with land costs

Chromosome-breakage genomic instability and chromothripsis in breast cancer

Background: Chromosomal breakage followed by faulty DNA repair leads to gene amplifications and deletions in cancers. However, the mere assessment of the extent of genomic changes, amplifications and deletions may reduce the complexity of genomic data observed by array comparative genomic hybridization (array CGH). We present here a novel approach to array CGH data analysis, which focuses on putative breakpoints responsible for rearrangements within the genome. Results: We performed array comparative genomic hybridization in 29 primary tumors from high risk patients with breast cancer. The specimens were flow sorted according to ploidy to increase tumor cell purity prior to array CGH. We describe the number of chromosomal breaks as well as the patterns of breaks on individual chromosomes in each tumor. There were differences in chromosomal breakage patterns between the 3 clinical subtypes of breast cancers, although the highest density of breaks occurred at chromosome 17 in all subtypes, suggesting a particular proclivity of this chromosome for breaks. We also observed chromothripsis affecting various chromosomes in 41% of high risk breast cancers. Conclusions: Our results provide a new insight into the genomic complexity of breast cancer. Genomic instability dependent on chromosomal breakage events is not stochastic, targeting some chromosomes clearly more than others. We report a much higher percentage of chromothripsis than described previously in other cancers and this suggests that massive genomic rearrangements occurring in a single catastrophic event may shape many breast cancer genomes

Negotiating daughterhood and strangerhood: retrospective accounts of serial migration

Most considerations of daughtering and mothering take for granted that the subjectivities of mothers and daughters are negotiated in contexts of physical proximity throughout daughters’ childhoods. Yet many mothers and daughters spend periods separated from each other, sometimes across national borders. Globally, an increasing number of children experience life in transnational families. This paper examines the retrospective narratives of four women who were serial migrants as children (whose parents migrated before they did) . It focuses on their accounts of the reunion with their mothers and how these fit with the ways in which they construct their mother-daughter relationships. We take a psychosocial approach by using a psychoanalytically-informed reading of these narratives to acknowledge the complexities of the attachments produced in the context of migration and to attend to the multi-layered psychodynamics of the resulting relationships. The paper argues that serial migration positioned many of the daughters in a conflictual emotional landscape from which they had to negotiate ‘strangerhood’ in the context of sadness at leaving people to whom they were attached in order to join their mothers (or parents). As a result, many were resistant to being positioned as daughters, doing daughtering and being mothered in their new homes

Exclusive production of rho^0 rho^0 pairs in gamma-gamma collisions at RHIC

We discuss exclusive electromagnetic production of two neutral $\rho$ mesons in coherent photon-photon processes in ultrarelativistic heavy-ion collisions. The cross section is calculated in the equivalent photon approximation (EPA). Both uncertainties of the flux factors and photon-photon cross sections are discussed in details. We show that inclusion of precise charge densities in nuclei is essential for realistic evaluations of the nuclear photon-photon cross sections. We find that the cross section, especially with realistic flux factors, is sensitive to low energy in the subsystem $\gamma \gamma \to \rho^0 \rho^0$. The experimental data for the $\gamma \gamma \to \rho^0 \rho^0$ cross section extracted from $e^+ e^-$ collisions are parametrized and used to estimate the nucleus-nucleus cross section. In addition, we include vector-dominance-model(VDM)--Regge contribution which becomes important at large photon-photon energy. Large nuclear cross sections are obtained. We discuss a possibility of focusing on the large-energy component. We find that both $\rho^0$ mesons are produced predominantly at midrapidities and could be measured by the STAR collaboration at RHIC.Comment: 11 pages, 7 figures; reference added/correcte

Spin instabilities and quantum phase transitions in integral and fractional quantum Hall states

The inter-Landau-level spin excitations of quantum Hall states at filling factors nu=2 and 4/3 are investigated by exact numerical diagonalization for the situation in which the cyclotron (hbar*omega_c) and Zeeman (E_Z) splittings are comparable. The relevant quasiparticles and their interactions are studied, including stable spin wave and skyrmion bound states. For nu=2, a spin instability at a finite value of epsilon=hbar*omega_c-E_Z leads to an abrupt paramagnetic to ferromagnetic transition, in agreement with the mean-field approximation. However, for nu=4/3 a new and unexpected quantum phase transition is found which involves a gradual change from paramagnetic to ferromagnetic occupancy of the partially filled Landau level as epsilon is decreased.Comment: 4 pages, 5 figures, submitted to Phys.Rev.Let