Erratum to: Comparative Studies of the Growth and Characterization of Germanium Epitaxial Film on Silicon (001) with 0° and 6° Offcut

In the original article we presented results that show that the strain in germanium (Ge) epitaxial films grown directly on a silicon (Si) (001) with 6° offcut has a tensile strain of 0.6%. This strain value is much higher than the typical tensile strain value of 0.2% reported for Ge/Si. This discrepancy is due unintentional omission of the Si offcut angle and azimuth angle (φ) of the sample during high-resolution x-ray diffraction (HRXRD) measurement, and it has unfortunately resulted in a misleading result

The theoretical direct-band-gap optical gain of Germanium nanowires

We calculate the electronic structures of Germanium nanowires by taking the effective-mass theory. The electron and hole states at the G-valley are studied via the eight-band k.p theory. For the [111] L-valley, we expand the envelope wave function using Bessel functions to calculate the energies of the electron states for the first time. The results show that the energy dispersion curves of electron states at the L-valley are almost parabolic irrespective of the radius of Germanium nanowires. Based on the electronic structures, the density of states of Germanium nanowires are also obtained, and we find that the conduction band density of states mostly come from the electron states at the L-valley because of the eight equivalent degenerate L points in Germanium. Furthermore, the optical gain spectra of Germanium nanowires are investigated. The calculations show that there are no optical gain along z direction even though the injected carrier density is 4x1019 cm-3 when the doping concentration is zero, and a remarkable optical gain can be obtained when the injected carrier density is close to 1x1020 cm-3, since a large amount of electrons will prefer to occupy the low-energy L-valley. In this case, the negative optical gain will be encountered considering free-carrier absorption loss as the increase of the diameter. We also investigate the optical gain along z direction as functions of the doping concentration and injected carrier density for the doped Germanium nanowires. When taking into account free-carrier absorption loss, the calculated results show that a positive net peak gain is most likely to occur in the heavily doped nanowires with smaller diameters. Our theoretical studies are valuable in providing a guidance for the applications of Germanium nanowires in the field of microelectronics and optoelectronics

Unveiling the practices and challenges of professional learning community in a Malaysia Chinese School

Professional learning community (PLC) studies in the Asian Chinese nations remain scarce despite the emerging interest in the practice of PLC beyond the Western context. This study attempts to provide an understanding of the practices of PLC and challenges in implementing PLC in a Malaysian Chinese culture–dominated secondary school. This qualitative study used a phenomenological constructivist approach as a strategy of inquiry. Semi-structured interview data were collected from six middle leaders and ordinary teachers in a national-type Chinese secondary school in the northern region. Findings informed three existing PLC practices at the school level, namely, (a) peer coaching, (b) sharing of personal practices, and (c) professional development courses. However, the practice of PLC encounters various challenges, including excessive workload, teachers’ passive attitudes, unsupportive conditions in the school, poor execution of PLC by the school community, and a vague understanding of PLC. Interestingly, this study identified two uncovered challenges hindering the development of PLC: misconception about PLC and lack of supervision from the authority. Implications and future studies are presented

Unveiling the practices and challenges of professional learning community in a Malaysian Chinese Secondary School

Professional learning community (PLC) studies in the Asian Chinese nations remain scarce despite the emerging interest in the practice of PLC beyond the Western context. This study attempts to provide an understanding of the practices of PLC and challenges in implementing PLC in a Malaysian Chinese culture–dominated secondary school. This qualitative study used a phenomenological constructivist approach as a strategy of inquiry. Semi-structured interview data were collected from six middle leaders and ordinary teachers in a national-type Chinese secondary school in the northern region. Findings informed three existing PLC practices at the school level, namely, (a) peer coaching, (b) sharing of personal practices, and (c) professional development courses. However, the practice of PLC encounters various challenges, including excessive workload, teachers’ passive attitudes, unsupportive conditions in the school, poor execution of PLC by the school community, and a vague understanding of PLC. Interestingly, this study identified two uncovered challenges hindering the development of PLC: misconception about PLC and lack of supervision from the authority. Implications and future studies are presented

Unveiling the Practices and Challenges of Professional Learning Community in a Malaysian Chinese Secondary School

Professional learning community (PLC) studies in the Asian Chinese nations remain scarce despite the emerging interest in the practice of PLC beyond the Western context. This study attempts to provide an understanding of the practices of PLC and challenges in implementing PLC in a Malaysian Chinese culture– dominated secondary school. This qualitative study used a phenomenological constructivist approach as a strategy of inquiry. Semi-structured interview data were collected from six middle leaders and ordinary teachers in a national-type Chinese secondary school in the northern region. Findings informed three existing PLC practices at the school level, namely, (a) peer coaching, (b) sharing of personal practices, and (c) professional development courses. However, the practice of PLC encounters various challenges, including excessive workload, teachers’ passive attitudes, unsupportive conditions in the school, poor execution of PLC by the school community, and a vague understanding of PLC. Interestingly, this study identified two uncovered challenges hindering the development of PLC: misconception about PLC and lack of supervision from the authority. Implications and future studies are presented

Quantitation of green fluorescent protein using a gel-based imaging method.

Green fluorescent protein (GFP) is a versatile reporter protein and has been widely used in biological research. However, its quantitation requires expensive equipment such as a spectrofluorometer. In the current study, a gel documentation imaging system using a native polyacrylamide gel for the quantitation of GFP was developed. The assay was evaluated for its precision, linearity, reproducibility, and sensitivity in the presence of Escherichia coli cells and was compared with the spectrofluorometric method. Using this newly established, gel-based imaging technique; the amount of GFP can be quantified accurately

Secondary Household Transmission of SARS, Singapore

Secondary household transmission of severe acute respiratory syndrome (SARS) was studied in 114 households involving 417 contacts. The attack rate was low (6.2%). Occupation of the index case was the factor that most influenced household transmission (adjusted hazard ratio for healthcare workers 0.157; 95% confidence interval 0.042 to 0.588)