The Rumsfeld Effect: The unknown unknown

A set of studies tested whether people can use awareness of ignorance to provide enhanced test consistency over time if they are allowed to place uncertain items into a “don’t know” category. For factual knowledge this did occur, but for a range of other forms of knowledge relating to conceptual knowledge and personal identity, no such effect was seen. Known unknowns would appear to be largely restricted to factual kinds of knowledge

Optimum phase-shift estimation and the quantum description of the phase difference

The problem of a correct quantum description of the phase difference is examined from the perspective of parameter estimation theory. It is shown that an optimum phase-shift measurement defines a phase difference operator which coincides with other approaches to the same problem. We also study the fundamental limit to the accuracy of a phase difference shift detection. We show that this limit can be reached by a measurement having countable outcomes despite the fact that a phase shift can take any value. We show that this is the case of the phase difference operator defined by an optimum phase-shift measurement

A line confusion-limited millimeter survey of Orion KL. III. Sulfur oxide species

We present a study of the sulfur-bearing species detected in a line confusion-limited survey towards Orion KL performed with the IRAM 30m telescope in the range 80-281 GHz. The study is part of an analysis of the line survey divided into families of molecules. Our aim is to derive accurate physical conditions and molecular abundances in the different components of Orion KL from observed SO and SO2 lines. First we assumed LTE conditions obtain rotational temperatures. We then used a radiative transfer model, assuming either LVG or LTE excitation to derive column densities of these molecules in the different components of Orion KL. We have detected 68 lines of SO, 34SO, 33SO, and S18O and 653 lines of SO2, 34SO2, 33SO2, SO18O and SO2 v2=1. We provide column densities for all of them and also upper limits for the column densities of S17O, 36SO, 34S18O, SO17O and 34SO2 v2=1 and for several undetected sulfur-bearing species. In addition, we present 2'x2' maps around Orion IRc2 of SO2 transitions with energies from 19 to 131 K and also maps with four transitions of SO, 34SO and 34SO2. We observe an elongation of the gas along the NE-SW direction. An unexpected emission peak appears at 20.5 km/s in most lines of SO and SO2. A study of the spatial distribution of this emission feature shows that it is a new component ~5" in diameter, which lies ~4" west of IRc2. We suggest the emission from this feature is related to shocks associated to the BN object. The highest column densities for SO and SO2 are found in the high-velocity plateau (a region dominated by shocks) and in the hot core. These values are up to three orders of magnitude higher than the results for the ridge components. We also find high column densities for their isotopologues in both components. Therefore, we conclude that SO and SO2 are good tracers, not only of regions affected by shocks, but also of regions with warm dense gas.Comment: Paper (ref AA/2013/21285) accepted for publication by A&A. 52 Pages, 26 figures, 13 table

Contribution of an alveolar cell of origin to the high-grade malignant phenotype of pregnancy-associated breast cancer.

Pregnancy-associated breast cancers (PABCs) are tumors diagnosed during pregnancy or up to 5 years following parturition, and are usually high-grade, connective tissue-rich, and estrogen receptor (ER)/progesterone receptor-negative. Little is known about the cellular origin of PABCs or the mechanisms by which PABCs are initiated. Using the RCAS retrovirus to deliver the ErbB2 oncogene into the mammary epithelium of our previously reported MMTV-tva transgenic mice, we detected high-grade, poorly differentiated, stroma-rich and ER-negative tumors during pregnancy and lactation. These high-grade and stroma-rich tumors were less frequent in involuted mice or in age-matched nulliparous mice. More importantly, by generating a WAP-tva transgenic line for expression of ErbB2 selectively in WAP(+) mammary alveolar cells, we found that tumors had similar morphological phenotypes (high grade, poorly differentiated, stroma-rich and ER-negative), irrespective of the time since pregnancy and even in the absence of pregnancy. These data suggest that PABCs arise preferentially from an alveolar cell population that expands during pregnancy and lactation. This somatic mouse model may also be useful for preclinical testing of new prophylactic and therapeutic strategies against PABC

F-DCTCP: Fair Congestion Control for SDN-Based Data Center Networks

Network congestion control and management has long been a major issue in providing low-latency, high throughput and high link-utilisation. In particular, Data Center Network (DCN) environments, often dominated by partition-aggregate workloads, suffer performance collapse due to TCP Incast caused by inadequate congestion control parameters. This paper proposes a step in solving this problem. In particular, we describe a novel framework to overcome and control congestion in DCNs based on Software Defined Networking (SDN). We propose a native SDN-based congestion control mechanism, termed Fair Data Center TCP (F-DCTCP). As we shall see, the experimental results show that F-DCTCP outperforms all previous proposals by providing the best combined overall performance in terms of throughout, fairness and flow completion times, making it highly attractive for next generation networks

Extended warm gas in Orion KL as probed by methyl cyanide

In order to study the temperature distribution of the extended gas within the Orion Kleinmann-Low nebula, we have mapped the emission by methyl cyanide (CH3CN) in its J=6_K-5_K, J=12_K-11_K, J=13_K-12_K, and J=14_K-13_K transitions at an average angular resolution of ~10 arcsec (22 arcsec for the 6_K-5_K lines), as part of a new 2D line survey of this region using the IRAM 30m telescope. These fully sampled maps show extended emission from warm gas to the northeast of IRc2 and the distinct kinematic signatures of the hot core and compact ridge source components. We have constructed population diagrams for the four sets of K-ladder emission lines at each position in the maps and have derived rotational excitation temperatures and total beam-averaged column densities from the fitted slopes. In addition, we have fitted LVG model spectra to the observations to determine best-fit physical parameters at each map position, yielding the distribution of kinetic temperatures across the region. The resulting temperature maps reveal a region of hot (T > 350 K) material surrounding the northeastern edge of the hot core, whereas the column density distribution is more uniform and peaks near the position of IRc2. We attribute this region of hot gas to shock heating caused by the impact of outflowing material from active star formation in the region, as indicated by the presence of broad CH3CN lines. This scenario is consistent with predictions from C-shock chemical models that suggest that gas-phase methyl cyanide survives in the post-shock gas and can be somewhat enhanced due to sputtering of grain mantles in the passing shock front.Comment: 24 pages, 20 figures, accepted for publication in A&

Organisational Culture and Employees Commitment in Public Tertiary Institutions in Lagos State, Nigeria

DU study investigated the relationship between organizational culture and employees' C0111111ltment in public tertiary institutions in Lagos State, Nigeria. Four hypotheses were tated In this study. The descriptive research design type was adopted for the study. The population of the study comprises all the non-teaching and teaching employees in public tertiary institutions in Lagos State. The simple random sampling technique was first adopted to select four out of the seven public tertiary institutions in Lagos State for the study. The simple random sampling was fUrther used to select 50 employees from each of the four public tertiary institutions comprising a total of 200 samples for the study. An instrument tagged "Organizational Culture and Employees Commitment Questionnaire" was used to collect data for the study. The instrument was validated and a reliability coefficient of 0. 78 was obtained for the instrument. Data collected were analyzed using descriptive and inferential statistics. Results from the data analysis indicated that significant relationship exist between organizational culture and employees' commitment in public tertiary institutions in Lagos State. It was fUrther found that significant difference exist in the commitment of employees of different sex, ages and length of service to their institutions in Lagos State should Management improve on the cu"ent rewards system in their institutions to enhance employees' commitment levels as well as output among other

An Analysis of Factors Influencing Hiring/ Placement of University Graduates in Nigeria

1bia study notes the alarming rate of graduate unemployment and analyses the factors iaftuencing labour market demand for University graduates in Nigeria. A total of II 0 Labour Orpnizations was randomly sampled within Lagos metropolis. The study adopts a descriptive survey design. With the aid of a structured questionnaire and unstructured interview questions, relevant information was collected. Four hypotheses were postulated and tested at 0.05 level of significance using the chi-square. Finding shows that there are significant relationships between the experience, Government's economic policies, Quality of degree, Area of specialization and hiring I placement of Labour by Employer. The study concludes by suggesting the way out for the endemic state of unemployment in general and graduates from Nigeria Universities in particular