7% was error variance ( σerror2), which includes the variance due

7% was error variance ( σerror2), which includes the variance due to rater unreliability. The calculation of the intraclass correlation coefficient for absolute agreement between raters yielded an ICCa,1 of 0.943, which indicates excellent interrater reliability. 48.1% INK 128 order of the variance can be attributed to score differences between residents, while 45.5% is attributable to score differences between consultations. This variance component represents genuine residents-by-consultation-interaction variance. The inconsistency coefficient for all consultation combinations was

0.482. The correlation between the average score of the first and second consultations and the inconsistency score (R0,inconsist) was almost zero (−0.044) for all consultation combinations. The mean of score differences Rapamycin between the first and

second consultations, indicated by μ  dif, did not differ between the similar and dissimilar consultation combinations (0.030 and −0.533, t   = 1.31, df   = 48, p   ≥ .05). However, the distributions of inconsistency scores differed significantly between the similar and dissimilar consultations (Mann–Whitney U   test, p   < .05). The variance components also differed significantly between the similar and dissimilar consultation combinations. In the similar consultation combinations, the major proportion of variance (65.1%) was linked to differences between residents ( σresidents2), while in the dissimilar consultation combinations, the major proportion of the variance (67.5%) was linked to differences in residents’ performance between consultations during ( σresid×consult2). Thus, the inconsistency coefficients ( Rinconsist2) of the similar and dissimilar consultation combinations were also different (F = 16.41, p < .01). The Spearman correlation coefficient between the average score of the first and second consultations and the inconsistency scores (R0,inconsist) was significant for the dissimilar consultation combinations (−0.538), but not for the similar consultation combinations (0.111). CST background had a significant effect on the average scores of all consultation combinations (Table 3, η2 = 0.243, F = 7.53,

p < .01). However, the CST background effect was only present in the BBN consultations (η2 = 0.433, F = 9.93, p < .01) and in the PMD consultations (η2 = 0.209, F = 3.83, p < .05). CST background had no effect on the performance in the other consultations and had no effect on the inconsistency scores in any of the consultation combinations (Mann–Whitney U tests). Reliability and generalizability studies consider performance inconsistency between consultations as a measurement error. However, physicians are expected to communicate equally well in all consultations. Adequate communication in some consultations but mediocre or inadequate communication in others is unacceptable. In this study, we thus explored the inconsistency of residents’ communication performance in challenging consultations.

The hydrological droughts on daily time scale at low truncation l

The hydrological droughts on daily time scale at low truncation levels

such as Q90, Q95 have Lumacaftor order also been attempted on non-stationary daily flows using the frequency analysis of observed durations and magnitudes (Zelenhasic and Salvai, 1987 and Tallaksen et al., 1997). Although the assessment and prediction of meteorological droughts on weekly time scale have been practiced using the Palmer Drought Severity Index (PDSI) or Standardized Precipitation Index (SPI), in literature only a few studies on the modeling of hydrological droughts on weekly time scale have been reported. The analysis of hydrological droughts on weekly time scale is desirable because effects of droughts are more palpable in agricultural production, municipal water supplies, small-scale hydro generation etc. The development of suitable predictive and assessment tools for hydrologic droughts at weekly time scale would be useful in managing available water resources

and off-setting effects of droughts. This paper attempts to develop suitable methodology to analyze and predict hydrological droughts at weekly time scale. The paper also embodies the results of drought models for comparative purposes at annual and monthly time scales in Canadian BYL719 streamflows. It has been observed (Bonacci, 1993, Woo and Tarhule, 1994, Sharma, 1997 and Sharma, 2000) that in general the drought intensity (I, i.e. MT = I × LT) is poorly Bay 11-7085 correlated to LT. In view of a poor correlation (i.e. near independence) between these

two entities, the above relationship can be expressed in terms of expectations as E(MT) = E(I) × E(LT), which allows the prediction of drought magnitude with a priori knowledge of drought length. The drought intensity (I) can be modeled satisfactorily by the truncated normal distribution of SHI values which are laying below the truncation level. The modeling of drought length or duration (LT) is therefore essential in addressing the issues related to hydrological droughts. In the past, the theorem of extremes of random numbers of random variables ( Todorovic and Woolhiser, 1975; referred to hereafter as the extreme number theorem) has been used to model LT on annual flow series ( Sen, 1980a, Sharma, 1997, Sharma, 1998, Sharma, 2000, Panu and Sharma, 2002 and Panu and Sharma, 2009) and monthly flow series ( Sharma and Panu, 2008). Further, Sharma and Panu (2010) noted that the above theorem breaks down when the SHI sequences are strongly dependent (i.e. lag-1 autocorrelation being above 0.50) to the first order and/or extend to the second or higher order dependence (in case of weekly time scale). The monthly and weekly SHI sequences exhibit this tendency when the rivers are originating in lakes or passing through them. Under these circumstances, a second order Markov chain model tends to recover the analysis for modeling LT.

67% of the patients included were on prophylaxis Nevertheless,

67% of the patients included were on prophylaxis. Nevertheless,

re-admissions in this sub-group were not statistically significantly different from those not on prophylaxis. It is possible that no significance was found owing to a lack of statistical power based on the small number of patients included in the study. It was not possible to evaluate in this study if SBP patients on proton pump inhibitors had a higher rate of SBP than those who were not. In further studies this should be assessed. The fact that the study was retrospective, made it more difficult to analyze certain variables, as data was missing in some patients files. Patient search and selection was limited to patients with SBP SB431542 in vivo diagnosis, based on the CDI-10 classification, by the time of discharge or BIBW2992 chemical structure death. There might have been more patients in whom this diagnosis was not done or who were not correctly codified. The authors have no conflict of interest to declare. The authors would like to thank Rui Medeiros for the statistical analysis done. “
“A bactéria Clostridium difficile (C. difficile), um bacilo gram positivo, anaeróbio, formador de esporos e produtor de toxinas patogénicas (A e B) é responsável pela quase totalidade dos casos de colite pseudomembranosa (CPM) e por até 20% dos casos de diarreia associada aos antibióticos sem colite 1 and 2.

É a causa mais comum de diarreia nosocomial nos países desenvolvidos e, desde 1980, a sua incidência, morbilidade e mortalidade a nível mundial têm aumentado 3, 4 and 5. Recentemente, uma nova estirpe (BI/NAP1/027) produtora de uma toxina binária e resistente às quinolonas, emergiu como responsável por vários surtos no Canadá

e EUA 6. Dados recolhidos desses surtos referiam taxas de incidência 4 vezes e meia superiores às taxas históricas e um aumento de 5 vezes na mortalidade 7. Na Europa, esta estirpe http://www.selleck.co.jp/products/Verteporfin(Visudyne).html já foi detetada em 16 países, com 9 deles a reportarem surtos 8. Os fatores de risco mais consistentemente associados ao desenvolvimento da doença são a antibioterapia prévia, a idade avançada (especialmente acima dos 60 anos de idade) e o tempo de hospitalização9 and 10. Apesar de qualquer antibiótico poder estar implicado, os mais frequentemente envolvidos são a clindamicina, as cefalosporinas de terceira geração e as penicilinas de largo espetro4. Recentemente, as quinolonas têm vindo a assumir um papel preponderante11. Outros fatores de risco que têm sido descritos são a gravidade das comorbilidades, a entubação nasogástrica, a supressão da acidez gástrica, a permanência em Unidade de Cuidados Intensivos (UCI) e a exposição a estados imunossupressivos (transplantação, síndrome de imunodeficiência adquirida, doença inflamatória intestinal e neoplasias)12. O espetro da lesão provocada por esta bactéria engloba o portador assintomático, a diarreia associada aos antibióticos, a CPM e a colite fulminante2. Cerca de 3-8% dos doentes com infeção por C.

However, uncertainties were relatively high during low flow seaso

However, uncertainties were relatively high during low flow seasons, which can be seen as a model deficiency in simulating groundwater flow ( Rostamian et al., 2008). The model performance metric values in Table 3, and P-factor, and R-factor indicate the model is reliable in simulating Brahmaputra basin streamflow. Graphical comparisons of observed and simulated streamflow at a monthly scale for calibration (1988–1997), validation (1998–2004), and baseline (1988–2004) periods are shown in Fig. 3. In general, the model accurately tracked the observed streamflow for the time periods, although some selleck inhibitor peak flow months were underpredicted during calibration, but the under-prediction was less during validation,

possibly due to less temporal variability in the precipitation. Monthly flow statistics in Table 3 suggest a strong correlation between simulated Selleckchem PLX3397 and observed streamflow in all three periods. The NS coefficients for simulated streamflows were 0.85, 0.88, and 0.73 for the calibration, validation, and baseline periods, respectively. These coefficients suggest that model performance for monthly streamflow was relatively better than daily. The model underpredicted streamflows for the calibration and validation periods by 3.2% and 4.4%, respectively. The regression lines and sum difference plots reveal that the underprediction occurred primarily during higher flows (Fig. 3b, c, e, and f). Literature suggests that SWAT

is not designed to simulate extreme events and the model usually underpredicts the largest flow events (Chu Aurora Kinase and Shirmohammadi, 2004 and Tolson and Shoemaker, 2004). However, a positive bias for simulated streamflow of 2.9% was noticeable for the baseline. The notable 1999 overprediction of peak flow may have contributed to this positive bias in simulated streamflow. Overall, the SWAT model was able to simulate well the actual hydrological conditions in the Brahmaputra basin. Ten sensitive parameters were used to calibrate the model (Table 1). These parameters primarily represented surface runoff, groundwater, snow, ET, and the routing process for the basin’s hydrology.

The values for the following parameters were found to be commonly used in other studies to calibrate the SWAT model: CN2 (SCS runoff curve number for moisture condition II), ESCO (soil evaporation compensation factor), ALPHA_BF (baseflow alpha factor), SLSUBBSN (average slope length), GWQMN (threshold depth of water in the shallow aquifer required for return flow to occur), and GW_REVAP (ground revap coefficient) (Cibin et al., 2010, Ghaffari et al., 2010, Heuvelmans et al., 1999, Mutenyo et al., 2013 and Wu et al., 2012a). While the final fitted values were optimized by the automatic calibration algorithm SUFI2, the values were checked for correspondence to the basin characteristics and their underlying hydrological processes. The average CN2 value was 61. The baseflow alpha factor value of 0.

All previous studies that reported a costimulatory role of this m

All previous studies that reported a costimulatory role of this molecule were based on the use of monoclonal antibodies to trigger the CD150 molecule on T cells (Cocks et al., 1995, Aversa et al., 1997 and Howie et al., 2002). CD150 is a self-ligating molecule and no other binding partners have been described. Thus, we wanted to analyze whether the costimulatory effect was also observed upon engagement of T cell-expressed CD150 with its natural ligand. Therefore, we generated stimulator cells expressing CD150 in conjunction with anti-CD3. When co-culturing these stimulator cells with human T cells, no significant contribution of this interaction

to T cell proliferation RG7204 datasheet and cytokine production was observed (Fig. 5B,C). In some of our experiments reduced proliferation rates of human T cells were observed in the presence of human CD150 but additional experiments are required to

confirm that CD150 can function as a negative regulator of T cell responses. During APC–T cell interaction www.selleckchem.com/products/Cisplatin.html a complex interplay of numerous cell surface molecules modulates cellular immune responses by either enhancing or inhibiting T cell receptor complex signalling. Thus, assessing the function of individual costimulatory ligands using natural APC is a difficult task. With our T cell stimulator cells we have generated an experimental tool for studying individual costimulatory ligands in a cellular system, but detached from the context of numerous other molecules involved in the regulation of T cell activation that are expressed on professional APC. Whereas similar cellular systems that have been termed artificial APC (aAPC)

use cells engineered to express Fc-γ receptors (CD32 or CD64) and depend on the addition of anti-CD3 antibodies (Thomas et al., 2002, Suhoski et al., 2007 and Gong et al., 2008) we used cell lines that stably express membrane-bound anti-CD3 antibody fragments. Using different anti-CD3 expression constructs we have generated Rucaparib two cell clones that stably express different levels of anti-CD3 antibody fragments: A construct where the anti-CD3 antibody fragments are linked to the transmembrane domain of human CD28 molecules yielded Bw-aCD3low stimulator cells that give a weak signal 1 to human T cells, whereas a construct encoding anti-CD3 antibody fragments fused to the human CD14 molecule was used to generate cells expressing high levels of GPI-anchored anti-CD3 antibody fragments (Bw-aCD3high; Fig. 1). The GPI-anchored anti-CD3 antibody fragment is efficiently targeted to lipid rafts and has also successfully been used for the stimulation and manipulation of human T cells with immunosomes — virus-like particles decorated with TCR/CD3 ligands, costimulatory molecules and modified cytokines (Derdak et al., 2006, Kueng et al., 2007, Leb et al., 2009 and Kueng et al., 2010).

They were asked to pass a list with the number and the names of t

They were asked to pass a list with the number and the names of the persons within their organization that were willing to participate. After that, they received the necessary sampling material

from the WIV-ISP (Scientific Institute of Public Health). The blood samples themselves were taken by the occupational health physician of each organization. In addition, an e-mail address was opened ([email protected]) for any questions PLX4032 cell line related to the biomonitoring study in Wetteren. Emergency responders who presented themselves spontaneously but were not on the lists, were also accepted for the study. The study protocol was approved by the Ethical Committee of the Ghent University Hospital and an informed consent was signed by all participants prior to their participation in the study. The sampling took place from May 21 until June 28, i.e., days 17–55 after the train accident. The data collection was organized in collaboration with the occupation health services. Each participant provided venous blood, collected in a tube filled with EDTA for the determination of N-2-cyanoethylvaline (CEV). Urine samples were collected for the measurement of cotinine because smoking may influence the CEV concentration. All GW-572016 research buy emergency responders also filled in a short questionnaire, including (i) demographic information,

i.e., name, address, gender and date of birth; (ii) smoking status (non-smoker, ex-smoker, occasional smoker and daily smoker); (iii) some specific variables related to the sampling, i.e., the day and the hour at which blood and urine sampling took before place; (iv) a table with detailed information

on where participants had been in the night of and in the days following the train accident, i.e., <50 m, 50–250 m, 250–500 m, 500–1000 m, and >1000 m away from the train accident; by day between May 4–10; and (v) the use of respiratory protection (yes/no) in the night of and in the days following the train accident, by day between May 4–10. The function of the participants was provided by the emergency responder organizations. In total, 1054 emergency responders participated in the biomonitoring. Persons with missing value in either blood CEV measurements, urinary cotinine measurements, questionnaire (spatial and temporal information of the presence on-site between May 4–10), or transmission of the function, were omitted from the analyses of this article. The final study population consisted therefore of the 841 emergency responders. Blood samples were pre-treated within 24 h to obtain a lysate of erythrocytes. The pretreated samples were stored at −20 °C. Because of the need for substantial analyzing capacity, blood samples were sent on dry ice to three different laboratories specialized in CEV analyses where a modified Edman degradation was used for adduct dosimetry (Tornqvist et al., 1986 and Van Sittert et al., 1997).

The Baltic Sea biota consists of four types of natural immigrants

The Baltic Sea biota consists of four types of natural immigrants of different origin: freshwater, marineboreal, cold-water, and glacial relicts of freshwater and marine origin (Elmgren 1984). Fish species from other regions (like the Mediterranean or North Sea) are non-indigenous immigrants, occurring sporadically, and which should be regarded as merely an enrichment of the Baltic fish community (Grygiel & Trella 2007). Some authors,

I-BET-762 manufacturer like Elmgren and Hill, 1997 and Elmgren, 1984, regard the Baltic Sea, in comparison with other basins, as a unique example of an ecosystem inhabited by few species, functioning at a low level of biodiversity, whereas Grygiel & Trella (2007) consider the Baltic fish community to be of relatively high biodiversity. Be that as it may, there are some 120 marine fish species in the North Sea MG-132 concentration but only 69 in the western Baltic Sea (ICES subdivisions 22–24) (Aro 2000). There are well-documented reports on over 20 non-indigenous marine fish species (NIS), including just one typically invasive species – Neogobius melanostomus (Pallas, 1814) ( Skóra, 1996, Krzykawski et al., 2001, Bacevičius and Karalius, 2005, Grygiel and Trella, 2007, Lampart-Kałużniacka et al., 2007 and Czerniejewski et al., 2008). The occurrence of NIS has been reported not only from the Baltic

Sea, but also from the Mediterranean, considered to be one of the main hotspots Quisqualic acid for marine bioinvasions and is, among European seas, by far the major recipient of NIS, including macrophytes, invertebrates and fish. The most important vectors of NIS in this region are shipping, aquaculture and direct immigration via the Suez Canal. In recent decades, the rate of introductions into the Mediterranean Sea has increased, which has had both ecological and economic

impacts ( Kalogirou et al. 2010). Some species occur unexpectedly in new regions after an expansion of their natural distribution range (Mohr, 1988 and Nehring, 2002); one of these is the thicklip grey mullet, which occurs in the North Atlantic. Its range extends northwards to the Faroes and the British Isles, Iceland and southern Norway. Since the mid-1960s, the species has evidently been spreading from the North Sea into the western Baltic (Mohr 1988). Single specimens were caught in Flensburg Fjord and the Fehmarnsund in the mid-1970s, and in Kiel Fjord and the Trave estuary in the 1980s (Czerniejewski et al. 2008). Ehrich et al. (2006) put Chelon labrosus on the list of fish species occurring in German waters in the North Sea and western Baltic, but the frequency of occurrence in the total number of hauls was extremely low in the former region (0.01%), and zero in the latter one (studies conducted from 1958 to 2005).

, 2013) Variability in the studied developmental patterns could

, 2013). Variability in the studied developmental patterns could be the result of an absence of directional selection or can reflect a selection process to the local environment ( Bradshaw et al., 2004). As this study’s experimental rearing temperature corresponds to the natural coldest developmental conditions on La Reunion Island shores, the tropical strain was reared under a more stressful CT99021 molecular weight environment than the temperate strain

whose fitness is optimized for this average temperature. However, even among tropical strains of A. aegypti, developmental rates have been demonstrated to be heterogeneous under the same temperature ( Couret and Benedict, 2014). Different larval developmental rates between populations have previously been observed Screening Library price in other mosquito species like A. (Oc.) triseriatus ( Holzapfel and Bradshaw, 1981), but not in A. albopictus ( Waldock

et al., 2013). This underlines the need to compare several temperate and tropical strains in order to confirm our observations. Aedes species are particularly exposed to desiccation, and its serosal cuticle development is more effective than in other mosquito genera (Vargas et al., 2014). Interestingly, only the serosal cuticle’s complete secretion took place faster in our tropical strain as compared to our temperate strain. The first hypothesis to explain this kinetic difference is that this protection mechanism against a dried-up environment must be subject to a strong Buspirone HCl selective pressure, especially in the tropics where the threat of death by desiccation is extreme (Tauber et al., 1986). However A. albopictus eggs are laid in outdoor water containers likely to dry up, and most eggs in diapause process are laid during the favorable season when average temperature is still high in temperate area. The additional delay in the formation of serosal cuticle generated by diapause preparation incurs a longer period of sensitivity to desiccation in a context of strong evaporation. Thus the

induction of diapause syndrome could have hazardous effects on eggs, even if diapause-programmed eggs later offset this risk notably with a higher quantity of surface lipids on the chorion which increases desiccation resistance ( Sota and Mogi, 1992a and Urbanski et al., 2010a). The serosal cuticle is an important structure protecting from desiccation but not the only one ( Rezende et al., 2008). The second hypothesis is that tropical strains developed other structural and metabolic mechanisms to improve the egg’s waterproof quality, and counterbalance a more rapid but potentially weaker or thinner serosal cuticle. This hypothesis is supported by the presence of a higher quantity of surface hydrocarbons on tropical eggs than temperate eggs ( Urbanski et al., 2010a). Temperate strains would favor the production of a stronger or improved serosal cuticle than tropical strains, which requires a prolonged period of formation.

The longitudinal and transverse relaxation rates of the various

The longitudinal and transverse relaxation rates of the various

spin-states of the 15N-ammonium check details AX4 spin-system are calculated using the Bloch-Wangsness-Redfield theory [20], [21], [22] and [23]. We assume here that the geometric structure of the AX4 spin-system is that of a tetrahedron, which for ammonium means that the 15N nucleus is in the centre, with each of the four protons located at the corners of the tetrahedron (see below). Thus, the symmetry-adapted elements of an irreducible basis representation have symmetries that fall within the irreducible representations of the Td point group [24], that is, A1, A2, E, T1, T2. The total spin density operator that completely describes the spin-state of 15NH4+ can be written as a direct product of spin density operators describing Epacadostat the 15N and proton spin-states. The 15N and proton spin density operators can in turn be expressed as linear combinations

of a set of basis operators. Here we derive 15N relaxation rates in terms of two sets of proton spin density basis operators: (1) Proton spin density operators that are the projection operators of the eigenfunctions to the proton Zeeman Hamiltonian. These energy eigenfunctions are denote by |m1m2m3m4〉, where mi (i = 1, 2, 3, 4) is the eigenvalue of the Zeeman Hamiltonian (α ≡ 1/2, β ≡ −1/2). The corresponding projection operator, which is the relevant density operator element, is denoted by |m1m2m3m4〉〈m1m2m3m4|. (2) Proton spin density operators from the basis of Cartesian/shift operator basis, where each basis operator represents a combination HSP90 of longitudinal and zero-quantum magnetisations of the four protons, that is, Hz1, Hz2, … , Hz1Hz2, … , H+1H−2, … , Hz1Hz2Hz3Hz4,

where Hzi is the longitudinal product operator of proton i, and H+i and H−i are the corresponding shift (raising and lowering) operators. As shown below, we use group theory to derive symmetry-adapted proton spin eigenfunctions, thereby simplifying the calculation of the relaxation rates. Symmetry-adapted basis functions for the spin wavefunctions in tetrahedral T  d symmetry can be conveniently constructed with the basic tools of group theory. The major strength of using the symmetry-adapted basis functions, as opposed to non-symmetry adapted functions, is that time-evolutions are simpler since total-symmetric Hamiltonians (A  1 in the T  d point group) cannot mix functions with different symmetry. In the context of NMR spectroscopic investigations of AX4 spin-systems, this means that the time-evolution of the spin-system and the observed relaxation rates are more intuitive. Below we briefly outline how the symmetry-adapted basis functions, which are also eigenfunctions of the proton Zeeman Hamiltonian, H^Z, are constructed.

In addition, zymographic analysis demonstrated that some of these

In addition, zymographic analysis demonstrated that some of these strains were also able to release several molecules with the same proteolytic activity, such as gelatinase (data not shown). Environmental bacteria considered to display low virulence, however, such as Acinetobacter spp. encountered find more in the mucus of P. motoro, can also become a threat to the patient if delivered into the wound, due their ability to survive in damaged tissue and resist antibiotic treatments ( Sebeny et al., 2008 and Dallo and Weitao, 2010). For this reason, these bacteria are even more dangerous to immune-compromised people who cannot fully fight the infection

that can develop with serious consequences. In addition, severe secondary infection by environmental bacteria can also progress in immune-competent hosts, as demonstrated by Markov et al. (2007) in a clinical report that describes a case of necrotizing fasciitis ( Thompson et al., 1993) in an immune-competent Doramapimod concentration patient due to A. hydrophila acquired in brackish water. Necrotizing fasciitis due to V. alginolyticus and P. damsela have also been reported in immune-competent patients after marine stingray accidents, both organisms being rarely associated with human infections, and nearly always encountered in immune-compromised

hosts ( Barber and Swygert, 2000 and Ho et al., 1998). Other bacterial species such as C. freundii, which in this work was encountered both in P. motoro mucus and in environmental water, has also been isolated from a wound acquired during a stingray accident ( Fenner et al., 1989). In addition to bacterial infections, invasive fusariosis due to Fuscarium solani is also associated with injury acquired in a stingray accident ( Hiemenz et al., 1990). The clinical cases previously described highlight the importance Tyrosine-protein kinase BLK of both bacterial and fungal wound-infections in stingray accidents. It is also important to take into consideration the fact that most environmental bacteria are multi-drug resistant (Grobusch et al., 2001, Rennie et al., 2003, Valencia et al., 2004, Horii et al., 2005, Flattau et al., 2008 and Shak et al.,

2011). A. hydrophila resistant to amikacin, tobramycin and multiple ceplalosporins has been isolated from a polymicrobial infection acquired during a fall into freshwater ( Shak et al., 2011). Also, P. damsela with intermediate resistance to amikacin has been isolated from a wound acquired in a stingray accident ( Barber and Swygert, 2000). In our work, none of the strains isolated was resistant to this antibiotic, but 68% of all Gram-negative isolates were highly resistant to other types of beta-lactam antibiotics, indicating that they were able to produce beta-lactamases, which in case of mixed infections can be released into the wound and protect susceptible bacteria against this category of antibiotic ( Brook et al., 1983, Brook et al., 1984 and Brook, 2009).